JP2005046756A - Processing method for polluted bottom sediment at bottom of water - Google Patents

Processing method for polluted bottom sediment at bottom of water Download PDF

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JP2005046756A
JP2005046756A JP2003282511A JP2003282511A JP2005046756A JP 2005046756 A JP2005046756 A JP 2005046756A JP 2003282511 A JP2003282511 A JP 2003282511A JP 2003282511 A JP2003282511 A JP 2003282511A JP 2005046756 A JP2005046756 A JP 2005046756A
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JP4229272B2 (en
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Hiromi Shinpo
裕美 新保
Masahiro Tanaka
昌宏 田中
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Kajima Corp
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<P>PROBLEM TO BE SOLVED: To provide a processing method for polluted bottom sediment at the bottom of water, by which the widely spreading polluted bottom sediment can be processed economically and efficiently. <P>SOLUTION: A waterflow 10 having a density higher than that of bottom water is formed and sent along a polluted bottom 1 of water toward a recess 6 at the bottom 1, and the bottom 1 is agitated to suspend the bottom sediment 3 in the waterflow 10. A turbid waterflow 12 of a high density raised by suspending the polluted bottom sediment 3 is used to collect the bottom sediment 3 of the bottom 1 in the recess 6 for processing. Preferably, the high-density water flow 10 is formed by discharging water 21 of a high specific gravity onto the bottom 1 via a discharge pipe 14 with its lower end opened to the bottom 1. Further preferably, an agitating member 17 arranged at the lower end of the discharge pipe 14 is used to agitate the bottom sediment 3. Microbubbles are mixed into the high-density water flow 10 to suppress the precipitation of the suspended bottom sediment 3, and the turbid waterflow 12 mixed with the microbubbles supplies oxygen to the polluted bottom sediment at the bottom 1 for cleaning. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は水底汚染底質の処理方法に関し、とくに広範囲に分布した水底の汚染底質を処理又は処分する方法に関する。   The present invention relates to a method for treating bottom sediment, and more particularly, to a method for treating or disposing contaminated bottom sediment distributed over a wide area.

近年、ダイオキシン類や水銀、PCB等の汚染物質による土壌の汚染が大きな社会問題となっており、陸上の汚染土壌については遮断・封じ込めや浄化による土壌保全対策が進められている。他方、発生源から大気中に放出された汚染物質は河川等に到達し、主に粒子状物質に付着・吸着して海域や湖沼域に移行することが知られている。現実に東京湾等の閉鎖性水域では、底質中にダイオキシン等の汚染物質が含まれている場所が多数存在していることが報告されている。これら水底の汚染された底質についても、環境中への二次的な汚染発生源となる可能性があるため、陸上の汚染土壌と同様に適切な処理又は処分(以下、両者を纏めて処理ということがある。)が求められている。   In recent years, contamination of soil by pollutants such as dioxins, mercury, and PCBs has become a major social problem, and soil conservation measures are being promoted by blocking / containing and purifying terrestrial contaminated soil. On the other hand, it is known that pollutants released from the source to the atmosphere reach rivers, etc., and adhere to and adsorb mainly to particulate matter and migrate to the sea and lakes. In fact, in closed waters such as Tokyo Bay, it has been reported that there are many places where pollutants such as dioxin are contained in the sediment. These polluted bottom sediments may also be a secondary source of pollution into the environment, so appropriate disposal or disposal (hereinafter collectively referred to as both) Is sometimes required).

また湖沼・港湾・ダム湖等の閉鎖性水域では、水底に堆積したヘドロ等の汚染底質が嫌気化し、リン等の栄養塩を水中に溶出して水域の富栄養化の原因となり、硫化水素等を発生して魚介類等に悪影響を及ぼすことが知られている。水底の底質環境を改善する観点から、上述した汚染物質による汚染底質だけでなく、嫌気化した汚染底質の処理対策も重要な課題となっている。   In closed water areas such as lakes, harbors, and dam lakes, sludge deposits such as sludge accumulated on the bottom of the water become anaerobic, and nutrient salts such as phosphorus are eluted into the water, causing eutrophication of the water area. Are known to adversely affect seafood and the like. From the viewpoint of improving the bottom sediment environment of the bottom of the water, measures for treating not only the polluted bottom sediments but also the anaerobic polluted bottom sediments are important issues.

汚染物質で汚染された底質は、撹乱・拡散等による二次汚染の発生を避け、水質に及ぼす影響を最小限に抑えて処理する必要がある(非特許文献1参照)。このような処理方法の一例として特許文献1は、水底の汚染物質堆積層の所定領域を周囲から仕切り、周囲から仕切られた所定領域の汚染物質を攪拌し、攪拌された汚染物質を水上へ排出するか又は無害化する水底の浄化方法を提案している。例えば水底の所定水域を仕切函やケーソン等によって周囲から仕切り、仕切函等の内側で汚染物質の周囲への拡散を防止しつつ水底の底質を攪拌し、攪拌により浮遊した汚染物質をエアリフトや各種ポンプにより仕切函等の中空部を介して水上へ排出する。また、攪拌により浮遊した汚染物質に対して適当な薬剤を仕切函等の内側へ噴出することにより、浮遊した汚染物質を化学的に処理して無害化する。   Bottom sediment contaminated with pollutants must be treated with minimal influence on water quality by avoiding secondary contamination due to disturbance, diffusion, and the like (see Non-Patent Document 1). As an example of such a processing method, Patent Document 1 discloses that a predetermined region of a pollutant deposition layer on the bottom of the water is partitioned from the surroundings, the contaminants in the predetermined region partitioned from the surroundings are stirred, and the stirred contaminants are discharged onto the water. It proposes a method of purifying the bottom of the water that is detoxified or detoxified. For example, a predetermined water area of the bottom of the water is partitioned from the surroundings by a partition box or caisson, and the bottom of the bottom of the water is stirred while preventing the diffusion of the contaminants around the inside of the partition box or the like. It is discharged onto the water through a hollow part such as a partition box by various pumps. In addition, by spraying an appropriate drug to the inside of a partition box or the like with respect to the contaminants floating by stirring, the floating contaminants are chemically treated and rendered harmless.

また嫌気化した水底の底質を処理する方法として、嫌気化した水底へのエアレーションにより底質を浄化する方法が提案されている。例えば特許文献2は、旋回式エアレータにより閉鎖性水域の底部に微細な空気又は酸素の気泡(以下、マイクロバブルということがある。)を供給し、水域中に安定した上昇循環流を形成する閉鎖性水域の浄化方法を開示する。同文献が開示する旋回式エアレータは、噴出し式エアレータに比し気泡発生率が高く、水との接触面積が大きく且つ水中の滞留時間が長いマイクロバブルを生成できる。例えば、平均径が数100μm以下のマイクロバブルを閉鎖性水域の底部へ供給することにより、水域中に安定した上昇循環流を形成する。処理対象の底質が広範囲に分散している場合は、適宜距離間隔で多数の旋回式エアレータを配設することにより、閉鎖性水域内に多数の上昇循環流を形成する。   In addition, as a method for treating the bottom of the anaerobic water bottom, a method of purifying the bottom by aeration to the anaerobic water bottom has been proposed. For example, Patent Document 2 discloses a closed air flow in which fine air or oxygen bubbles (hereinafter sometimes referred to as microbubbles) are supplied to the bottom of a closed water area by a swirling aerator to form a stable upward circulation flow in the water area. Disclosed is a method for purifying natural waters. The revolving aerator disclosed in this document has a higher bubble generation rate than a jet aerator, and can generate microbubbles having a large contact area with water and a long residence time in water. For example, by supplying microbubbles having an average diameter of several hundred μm or less to the bottom of the closed water area, a stable upward circulation flow is formed in the water area. If the bottom sediment to be treated is dispersed over a wide range, a large number of ascending circulation flows are formed in the closed water area by arranging a large number of swirl aerators at appropriate distance intervals.

更に特許文献3は、嫌気化した底質を処理する方法として、水底の直上に位置する接底境界層の貧酸素化した海水よりも密度及び酸素濃度が高い高密度高酸素濃度水(例えば、エアレータで空気又は酸素を混入した低温海水又は塩分濃度上昇海水)を接底境界層に供給し、接底境界層内に所定酸素濃度を有する高酸素水層を形成する水底土壌の浄化方法を提案している。この方法では、水底の底層水全体に酸素を供給するのではなく、底層水中の最も酸素濃度が低い接底境界層内へ高密度高酸素濃度水を供給することにより接底境界層の有機物を分解し、その結果として底層水全体の貧酸素化を防止して水底土壌の浄化を図る。   Further, Patent Document 3 discloses a method for treating anaerobic bottom sediment, such as high density and high oxygen concentration water having a higher density and oxygen concentration than the oxygen-depleted seawater in the contacting boundary layer located immediately above the water bottom (for example, Proposes a method for purifying bottom soil that supplies low-temperature seawater mixed with air or oxygen (seawater with increased salinity concentration) to the contact boundary layer and forms a high oxygen water layer with a predetermined oxygen concentration in the contact boundary layer is doing. In this method, the organic matter in the bottom boundary layer is not supplied by supplying high density and high oxygen concentration water into the bottom boundary layer having the lowest oxygen concentration in the bottom water, rather than supplying oxygen to the entire bottom bottom water. It decomposes and as a result, purifies the bottom soil by preventing hypoxia of the entire bottom water.

環境省環境管理局「底質の処理・処分等に関する指針」平成14年8月30日Environmental Management Bureau, Ministry of the Environment, “Guidelines for the treatment and disposal of sediment” August 30, 2002 社団法人土木学会編、玉井信行著「新体系土木工学22 密度流の水理」技法堂出版株式会社、1992年4月20日第1版3刷、pp151-153Edited by Japan Society of Civil Engineers, Nobuyuki Tamai “New System Civil Engineering 22 Density Flow Hydraulics”, Technical Hall Publishing Co., Ltd., April 20, 1992, 1st Edition, 3rd edition, pp151-153 特開2002−364018号公報JP 2002-364018 A 特開平5−146796号公報Japanese Patent Laid-Open No. 5-146796 特開2000−129645号公報JP 2000-129645 A

しかし、特許文献1及び2の方法は、広範囲に分散した汚染底質を効率的に処理することが難しい問題点がある。実際の閉鎖性水域等では、汚染物質が粒子状物質に付着・吸着する形で広範囲に分布していると推定されている。特許文献1の方法は、所定水域を仕切函等によって周囲から仕切った上で汚染底質を処理するので1回当たりの処理範囲が限られており、汚染底質が広範囲に分散している場合は仕切函等の設置替え等が必要となって手間がかかると共に処理コストが嵩むので経済的・効率的な処理が難しくなる。また特許文献2の方法は、広範囲に嫌気化した汚染底質を浄化する場合に、水底に多数のエアレータを配置して送気し続ける必要があるので送気コストが膨大となり、やはり経済的・効率的な処理が難しい。   However, the methods of Patent Documents 1 and 2 have a problem that it is difficult to efficiently treat contaminated sediments dispersed over a wide range. In actual closed water areas, etc., it is estimated that pollutants are widely distributed in the form of adhering to and adsorbing particulate matter. In the method of Patent Document 1, since the contaminated sediment is treated after the predetermined water area is partitioned from the surroundings by a partition box or the like, the processing range per time is limited, and the contaminated sediment is widely dispersed However, since it is necessary to replace the partition box or the like, it takes time and processing costs increase, so that economical and efficient processing becomes difficult. In addition, the method of Patent Document 2 requires a large number of aerators on the bottom of the water when the polluted sediment that has been anaerobized over a wide area needs to be continuously supplied, so that the air supply cost becomes enormous. Efficient processing is difficult.

これに対し特許文献3の方法は、水底に供給した高密度高酸素濃度水が水底で広がって高酸素水層を形成するので、特許文献2の方法に比し広い範囲の水底の汚染底質を効率的に処理できる可能性がある。しかし、実際には水底の接底境界層に供給された酸素は急激に消費されるので、広範囲にわたる高酸素水層を形成するためには、ある程度大きな流速(流量)で高密度高酸素濃度水を供給し続ける必要がある。即ち特許文献3の方法も、広範囲に分布した汚染底質を処理するためには高酸素濃度水を供給(放流)するために大きなエネルギーが必要となる。更に小さなエネルギーで広範囲に分散した汚染底質を経済的・効率的に処理できる技術の開発が求められている。   On the other hand, in the method of Patent Document 3, high-density high oxygen concentration water supplied to the bottom of the water spreads at the bottom of the water to form a high oxygen water layer. Can be processed efficiently. However, since the oxygen supplied to the bottom boundary layer of the water bottom is actually consumed rapidly, in order to form a wide range of high oxygen water layer, high density and high oxygen concentration water at a certain large flow rate (flow rate). Need to continue to supply. That is, the method of Patent Document 3 also requires a large amount of energy for supplying (releasing) high oxygen concentration water in order to treat contaminated sediment distributed over a wide range. In addition, there is a need for the development of technology that can economically and efficiently treat contaminated sediment distributed over a wide area with small energy.

そこで本発明の目的は、広範囲に分布した汚染底質を経済的・効率的に処理できる水底汚染底質の処理方法を提供することにある。   SUMMARY OF THE INVENTION An object of the present invention is to provide a method for treating bottom sediments that can economically and efficiently treat polluted sediments distributed over a wide area.

本発明者等は、広範囲に分散した水底の汚染物質を効率的に処理するためには汚染物質を集めて処理することが有効であることに着目し、水底の汚染底質を窪地に集めて封じ込め又は浚渫する汚染底質処分方法を開発し、特願2002-204607号に開示した。この方法は、図7及び図8に示すように、水底1の底質が汚染された汚染域5に隣接して、窪地6へ向け下降する溝7を穿ち、汚染域5内の底層水2の密度を域外より高めつつ汚染域5内の底質を撹乱し(図8(B)及び(C)参照)、溝7へ潜入する高密度底層水2の密度流Lにより撹乱で巻き上げた底質(底質粒子)3を溝7へ導いて窪地6に集め、汚染底質3を窪地6に封じ込め又は窪地6から浚渫するものである。   The inventors of the present invention have focused on collecting and treating pollutants in order to efficiently treat a wide range of dispersed pollutants on the bottom of the water. A contaminated sediment disposal method to contain or trap was developed and disclosed in Japanese Patent Application No. 2002-204607. In this method, as shown in FIGS. 7 and 8, a groove 7 descending toward the depression 6 is formed adjacent to the contaminated area 5 where the bottom sediment of the water bottom 1 is contaminated, and the bottom water 2 in the contaminated area 5 is formed. The bottom of the polluted area 5 is disturbed while increasing its density from the outside (see FIGS. 8B and 8C), and the bottom is rolled up by disturbance by the density flow L of the high-density bottom water 2 that enters the groove 7. The material (sediment particles) 3 is guided to the groove 7 and collected in the depression 6, and the contaminated sediment 3 is contained in the depression 6 or dredged from the depression 6.

この方法は、汚染域5上にいわば人工的な密度躍層(pycnoline)を形成しながら汚染域5内の底質を撹乱するので(図8(B)参照)、撹乱時に巻き上がる汚染底質3の拡散を小さく抑え、汚染底質3を高密度底層水2中に閉じ込めて搬送できる。即ち、水質に及ぼす影響を最小限に抑えることができる。また、汚染域5内の高密度底層水2は周囲の低密度水の下方へ潜り込む密度流L(矢印L参照)となって溝7の底へ沈降し、更に溝7に沿って窪地6まで沈降するので、広範囲に分散した汚染物質を新たな搬送エネルギーを要さずに経済的に窪地6に集めることができる。更に、底質中の粒径の大きい粗粒分は集積過程で沈澱するが、底層水に浮遊する細粒分は窪地まで運ばれるので、とくに底質中の細粒分を選択的に集めて処理することができる。ダイオキシン等の汚染物質の大部分は底質中の細粒分に付着・吸着していると考えられており、図7及び図8の方法によれば、細粒分に付着・吸着した汚染物質を効率的且つ経済的に集めて処理することが可能である。   Since this method disturbs the sediment in the contaminated area 5 while forming an artificial pycnoline on the contaminated area 5 (see FIG. 8B), the contaminated sediment that rolls up during the disturbance. 3 is suppressed, and the contaminated sediment 3 can be confined and transported in the high-density bottom water 2. That is, the influence on the water quality can be minimized. Further, the high-density bottom water 2 in the contaminated area 5 becomes a density flow L (see arrow L) that sinks below the surrounding low-density water and settles to the bottom of the groove 7, and further along the groove 7 to the depression 6. Since it sinks, pollutants dispersed in a wide range can be economically collected in the depression 6 without requiring new transport energy. In addition, coarse particles with a large particle size in the sediment are settled during the accumulation process, but fine particles floating in the bottom water are transported to the depression, so that the fine particles in the sediment are collected selectively. Can be processed. Most of the pollutants such as dioxin are thought to adhere to and adsorb to fine particles in the bottom sediment. According to the method shown in FIGS. Can be collected and processed efficiently and economically.

本発明者は、図7及び図8の方法の有効性を確認するため、勾配約1/500で水深15cmの水路底面上に粗粒分と細粒分とを混合した模擬底質を敷設し、その底質上に水路内の水(以下、周囲水ということがある。)に対し比重1.000(密度差0.000)、比重1.003(密度差0.003)、及び比重1.030(密度差0.030)の高密度水を放流したときの底質の巻き上がり高さ、高密度水流の進行速度(密度流の流速)、底質中の細粒分と粗粒分の搬送量及び分級の程度を確認する実験を行った。その結果、高密度水と周囲水との密度差が大きいほど底質の巻き上げ高さが小さいこと、及び底質中の細粒分は粗粒分と分級されて遠くまで搬送されることを確認することができた。但し、底質を十分長い距離搬送するためには、高密度水と周囲水との密度差を大きくし、ある程度以上の大きな流速(流量)で高密度水を放流する必要があった。   In order to confirm the effectiveness of the method shown in FIGS. 7 and 8, the present inventor laid a simulated bottom sediment mixed with coarse and fine particles on the bottom of a channel having a gradient of about 1/500 and a water depth of 15 cm. High density of specific gravity 1.000 (density difference 0.000), specific gravity 1.003 (density difference 0.003), and specific gravity 1.030 (density difference 0.030) relative to the water in the channel (hereinafter sometimes referred to as ambient water) on the bottom sediment Experiments to confirm the roll-up height of the sediment when water is discharged, the traveling speed of the high-density water flow (velocity of the density flow), the transport amount of fine and coarse particles in the sediment, and the degree of classification went. As a result, it is confirmed that the higher the density difference between the high density water and the surrounding water, the lower the sediment height, and that the fine particles in the sediment are classified as coarse particles and transported far. We were able to. However, in order to transport the sediment for a sufficiently long distance, it is necessary to increase the density difference between the high-density water and the surrounding water and to discharge the high-density water at a flow rate (flow rate) larger than a certain level.

ところで、前記実験において本発明者は、放流した高密度水中で底質を巻き上げると、密度流の流速が理論値より大きくなり底質の搬送量が増加することを見出した。一般に密度流の理論的な流速は周囲水との密度差に応じて大きくなることが知られている(非特許文献2参照)。前記実験において密度流中に底質が巻き上がると、底質の浮遊によって密度流と周囲水との密度差が大きくなり、その結果として流速が速くなり底質が搬送されやすい状態になったと考えられる。この観察から本発明者は、図7及び図8の方法において、高密度底層水2の初期流速(流量)が小さい場合であっても、高密度底層水2中で底質3を撹乱して浮遊させ周囲水との密度差を大きくすることにより、高密度底層水2の搬送能力を高めることができるとの知見を得た。本発明は、この知見に基づく更なる研究・開発の結果、完成に至ったものである。   By the way, in the experiment, the present inventor has found that when the sediment is rolled up in the discharged high-density water, the flow rate of the density flow becomes larger than the theoretical value, and the amount of sediment transported increases. In general, it is known that the theoretical flow velocity of a density flow increases in accordance with the density difference from ambient water (see Non-Patent Document 2). In the above experiment, when the sediment is rolled up in the density flow, the density difference between the density flow and the surrounding water is increased due to the floating of the sediment, and as a result, the flow velocity is increased and the sediment is easily transported. It is done. From this observation, the present inventors disturbed the sediment 3 in the high-density bottom water 2 even in the case where the initial flow velocity (flow rate) of the high-density bottom water 2 is small in the method of FIGS. It was found that the carrying capacity of the high-density bottom layer water 2 can be increased by floating and increasing the density difference from the surrounding water. The present invention has been completed as a result of further research and development based on this finding.

図1の実施例を参照するに、本発明による水底汚染底質の処理方法は、汚染された水底1に沿って底層水より高密度の水流10を水底1の窪地6へ向けて形成しつつ水底1を撹乱して底質3を水流10中に浮遊させ、底質3の浮遊により密度を高めた濁り水流12により水底1の汚染底質3を窪地6に集めて処理してなるものである。   Referring to the embodiment of FIG. 1, the method for treating bottom sediment according to the present invention forms a water stream 10 having a higher density than bottom water along a contaminated bottom 1 toward a depression 6 in the bottom 1. The bottom sediment 3 is suspended in the water stream 10 by disturbing the bottom 1, and the polluted sediment 3 in the bottom 1 is collected in the depression 6 by the turbid water stream 12 whose density is increased by the suspension of the bottom sediment 3. is there.

好ましくは、高密度水流10を、下端が水底1に開口する放流管14経由で高比重水21を水底に放流することにより形成する。更に好ましくは、放流管14の下端に設けた撹乱部材17により水底1の底質3を撹乱する。   Preferably, the high-density water stream 10 is formed by discharging high specific gravity water 21 to the bottom of the water via a discharge pipe 14 whose lower end opens to the bottom 1. More preferably, the bottom sediment 3 of the bottom 1 is disturbed by a disturbing member 17 provided at the lower end of the discharge pipe 14.

本発明による水底汚染底質の処理方法は、水底に高密度水流を形成しつつ水底を撹乱して底質を浮遊させ、底質の浮遊により密度を高めた濁り水流により汚染底質を窪地に集めるので、次の顕著な効果を奏する。
(イ)高密度水流が少量であっても、底質の浮遊により底質搬送能力が大きい濁り水流とすることにより、水底の汚染底質を効率的に運ぶことができる。
(ロ)底層水中に形成した高密度水流の密度躍層内で底質を撹乱するので、高密度水流の上方への底質の拡散を小さく抑えることができる。
(ハ)濁り水流は密度流となって底質を搬送するので、新たな搬送エネルギーを必要とせず、広範囲に分散した汚染物質を経済的に集積できる。
(ニ)底質中の粒径の大きい底質は集積過程で沈澱するので、単位重量当たりの汚染物質含有量が高い細粒分を選択的に集積できる。
(ホ)広範囲にわたり低濃度で分散した汚染底質を、拡散させずに狭い窪地に経済的・効率的に集めて処理できるので、低コストの底質処理方法として実用化が期待できる。
The method of treating a bottom sediment according to the present invention is to create a high-density water flow at the bottom of the water, disturb the bottom of the water to float the bottom sediment, and turn the contaminated sediment into a depression by using a turbid water flow whose density is increased by floating the bottom sediment. Because it collects, it has the following remarkable effects.
(A) Even if the high-density water flow is small, the polluted sediment in the bottom of the water can be efficiently transported by using a turbid water flow having a large sediment transport capacity due to floating of the bottom sediment.
(B) Since the sediment is disturbed in the density crest of the high-density water stream formed in the bottom layer water, the diffusion of the bottom material above the high-density water stream can be suppressed to a low level.
(C) Since the turbid water flow becomes a density flow and conveys sediment, it does not require new conveyance energy, and it is possible to accumulate pollutants dispersed over a wide area economically.
(D) Since sediment with a large particle size in the sediment precipitates during the accumulation process, fine particles having a high contaminant content per unit weight can be selectively accumulated.
(E) Contaminated sediments dispersed at a low concentration over a wide range can be collected and treated economically and efficiently in narrow depressions without spreading, and thus practical application can be expected as a low-cost sediment treatment method.

図1は、汚染物質が広範囲に分布している汚染域5に本発明を適用した実施例を示す。このような汚染域5は、水底の汚染物質の分布を適当な計測・分析方法で求めることにより見出すことができる。本発明は、汚染域5上に近傍の窪地6へ向け、汚染域5の底質と接する底層水より密度が高い高密度水流10を形成する。窪地6は自然に形成されたものを利用できるが、汚染域5の近傍に適当な窪地6がない場合は、汚染域5の内側又は外側の適当な水底部位を適宜掘削して窪地6とすることができる。図7及び図8に示すように、汚染域5から窪地6へ向け下降する溝7を穿ち、高密度水流10を溝7に向けて形成し、溝7を介して窪地6へ流下させてもよい。   FIG. 1 shows an embodiment in which the present invention is applied to a contaminated area 5 where pollutants are widely distributed. Such a contaminated area 5 can be found by obtaining the distribution of pollutants at the bottom of the water by an appropriate measurement / analysis method. The present invention forms a high-density water stream 10 having a higher density than the bottom layer water in contact with the bottom sediment of the contaminated area 5 toward the nearby depression 6 on the contaminated area 5. Although the depression 6 can be formed naturally, if there is no suitable depression 6 in the vicinity of the contaminated area 5, an appropriate water bottom part inside or outside the contaminated area 5 is appropriately excavated to form the depression 6. be able to. As shown in FIGS. 7 and 8, a groove 7 that descends from the contaminated area 5 toward the depression 6 is drilled, and a high-density water flow 10 is formed toward the groove 7, and then flows down to the depression 6 through the groove 7. Good.

また本発明は、汚染域5上に高密度水流10を形成しつつ高密度水流10内で水底1を撹乱し、汚染域5の底質3を高密度水流10中に巻き上げ浮遊させて濁り水流12とする。図示例では、濁り水流12を点線斜線で示す。高密度水流10による密度躍層内で底質1を撹乱するので、巻き上げた底質3の高密度水流10の上方への拡散を抑え、底質3を高密度水流10内にいわば閉じ込めて濁り水流12とすることができる。濁り水流12は、高密度水流10に比し密度(即ち、底層水に対する密度差)が大きくなるので、上述したように高密度水流10に比し流速が速くなり、且つ、巻き上げた底質の濃度が高くなることにより、底質の搬送能力が高まる。本発明の特徴は、高密度水流10に底質3を浮遊させて濁り水流12とすることにより、水底1において水流10をいわば加速して底質3の搬送能力を高めることにある。   In addition, the present invention forms a high-density water stream 10 on the contaminated area 5 while disturbing the bottom 1 in the high-density water stream 10 and suspends the sediment 3 in the contaminated area 5 in the high-density water stream 10 and floats it. 12 In the illustrated example, the muddy water stream 12 is indicated by a dotted diagonal line. Since the sediment 1 is disturbed in the high-density water stream 10 by the high-density water stream 10, the upward diffusion of the high-density water stream 10 of the rolled-up bottom material 3 is suppressed, and the bottom material 3 is confined in the high-density water stream 10 so to speak. Water stream 12 can be used. The turbid water stream 12 has a higher density than the high-density water stream 10 (that is, a density difference with respect to the bottom water), so that the flow velocity is higher than that of the high-density water stream 10 as described above. By increasing the concentration, the ability to transport sediments is increased. A feature of the present invention is that the bottom sediment 3 is suspended in the high-density water stream 10 to form a turbid water stream 12, thereby accelerating the water stream 10 in the bottom 1 to enhance the transport capability of the bottom sediment 3.

図示例では、適当な方法で汚染域5の底層水の比重を求め、下端が水底1に開口する放流管14を介して底層水より比重が大きな高比重水21を水面4上から水底1へ放流することにより、汚染域5上に高密度水流10を形成している。例えば、水面4上の船舶に水冷却装置を搭載し、汚染域5の底層水の水温を測定し、汚染域5の底質を巻き上げない水深位置から汲み上げた水を冷却装置で前記測定した水温より低温に冷却し、その冷却水21を放流管14経由で汚染域5の水底1へ放流することにより高密度水流10を形成する。この場合、放流管14は断熱性の高いものとすることが望ましい。また、冷却水に代えて、汚染域5の底層水2の濃度(例えば、塩濃度)を測定し、測定濃度より高濃度に調製した高濃度水(例えば、高濃度塩水)を放流管14により水底1へ放流することにより、高密度水流10を形成してもよい。上述したように、本発明では水底1において高密度水10を濁り水流12として流速を高めることができるので、高密度水10は緩やかに放流すれば足り、放流量及び速度は最小限に抑えることができる。   In the illustrated example, the specific gravity of the bottom layer water in the contaminated area 5 is obtained by an appropriate method, and the high specific gravity water 21 having a larger specific gravity than the bottom layer water is passed from the water surface 4 to the bottom 1 through the discharge pipe 14 whose lower end opens to the bottom 1. By discharging, a high-density water flow 10 is formed on the contaminated area 5. For example, a water cooling device is mounted on a ship on the water surface 4, the water temperature of the bottom layer water in the contaminated area 5 is measured, and the water pumped up from the depth position where the bottom sediment of the contaminated area 5 is not rolled up is measured with the cooling device. The cooling water 21 is cooled to a lower temperature, and the cooling water 21 is discharged to the bottom 1 of the contaminated area 5 through the discharge pipe 14 to form a high-density water flow 10. In this case, it is desirable that the discharge pipe 14 has high heat insulation. Further, instead of the cooling water, the concentration (for example, salt concentration) of the bottom layer water 2 in the contaminated area 5 is measured, and the high concentration water (for example, high concentration salt water) prepared at a concentration higher than the measured concentration is discharged through the discharge pipe 14. A high-density water stream 10 may be formed by discharging it to the bottom 1. As described above, in the present invention, the flow rate can be increased by making the high-density water 10 turbid water flow 12 at the bottom 1, so that it is sufficient to discharge the high-density water 10 gently, and the discharge flow rate and speed should be minimized. Can do.

また図示例では、放流管14の下端に撹乱部材17を設け、撹乱部材17により水底1の底質3を撹乱して濁り水流12を形成している。撹乱部材17により底質3を直接撹乱するか、または撹乱部材17により高密度水流10中に流れの乱れMを形成し、その流れの乱れMにより底質3を撹乱することができる。但し、例えば図2に示すように放流管14の下端を汚染域5の底質3中に挿入し、高比重水21を底質3中へ放流することにより、図中の矢印Mで示すように高密度水流10中に底質3を巻き上げて濁り水流12とすることも可能である。従って、撹乱部材17は本発明に必須のものではない。撹乱部材17で底質3を撹乱する場合は、濁り水流12中に発生した乱れMによる底質3の拡散を防ぐため、後述するように撹乱部材17の下流側に整流化部材18を設け、濁り水流12を整流Cとした上で放流することが望ましい(図3及び図4参照)。   In the illustrated example, a disturbing member 17 is provided at the lower end of the discharge pipe 14, and the sediment 3 of the water bottom 1 is disturbed by the disturbing member 17 to form a turbid water stream 12. The bottom sediment 3 can be directly disturbed by the disturbance member 17, or the flow disturbance M can be formed in the high-density water flow 10 by the disturbance member 17, and the bottom sediment 3 can be disturbed by the flow disturbance M. However, for example, as shown in FIG. 2, the lower end of the discharge pipe 14 is inserted into the bottom sediment 3 of the contaminated area 5 to discharge the high specific gravity water 21 into the bottom sediment 3. It is also possible to wind up the bottom sediment 3 in the high-density water stream 10 to make a turbid water stream 12. Therefore, the disturbance member 17 is not essential for the present invention. When disturbing the bottom sediment 3 with the disturbing member 17, in order to prevent the bottom sediment 3 from diffusing due to the turbulence M generated in the turbid water flow 12, a rectifying member 18 is provided on the downstream side of the disturbing member 17, as will be described later. It is desirable to discharge the turbid water stream 12 after making it rectified C (see FIGS. 3 and 4).

密度を高めた濁り水流12は周囲の低密度の底層水の下方へ潜り込む密度流(図中の矢印L)となって移動し、逆に軽い底層水は濁り水流12の上へ乗り上がる密度流Uとなる。この濁り水流12の流れにより、水底1の汚染底質3を浮遊させつつ窪地6へ向け搬送できる。濁り水流12の密度は、底質3の拡散等による二次汚染の発生を防止できる範囲内で、底質3の撹乱及び浮遊量の増減によりある程度調整できる。また濁り水流12は、密度を高めることにより流速が高まると共に、図中の矢印τで示すように、底質3の掃流力(水底1との接触面におけるせん断応力)が高まる。濁り水流12中に浮遊する比較的大きな粗粒分は搬送過程で水底1に沈降するが、掃流力τにより搬送過程において水底1の底質3(特に細粒分)が濁り水流12中に巻き上がる。従って、底質3の撹乱により濁り水流12の密度をある程度高めておけば、その濁り水流12の搬送能力を大きく低下させずに水底1の底質3(特に細粒分)を窪地6まで運ぶことができる。   The turbid water stream 12 with an increased density moves as a density current (arrow L in the figure) that sinks below the surrounding low-density bottom water, and conversely, the light bottom water flows over the turbid water stream 12. U. This muddy water flow 12 allows the polluted sediment 3 on the bottom 1 to be conveyed toward the depression 6 while floating. The density of the turbid water stream 12 can be adjusted to some extent by disturbance of the bottom sediment 3 and increase / decrease in the amount of floating within the range in which secondary pollution due to diffusion of the bottom sediment 3 can be prevented. Further, the turbid water flow 12 has an increased flow velocity by increasing the density, and the scavenging force of the bottom sediment 3 (shear stress at the contact surface with the water bottom 1) increases as indicated by an arrow τ in the figure. The relatively large coarse particles floating in the turbid water stream 12 settle to the bottom 1 in the transport process, but the sediment 3 (particularly fine particles) of the bottom 1 in the transport process is trapped in the turbid water stream 12 by the tractive force τ. Roll up. Therefore, if the density of the turbid water stream 12 is increased to some extent by the disturbance of the bottom sediment 3, the sediment 3 (particularly fine particles) of the water bottom 1 is transported to the depression 6 without greatly reducing the conveying capacity of the turbid water stream 12. be able to.

本発明によれば、底質3の浮遊により密度を高めた濁り水流12により水底1の汚染底質3を窪地6へ搬送するので、底質3を浮遊させる前の高密度水流10は撹乱時の底質3の拡散を抑えることができる範囲内で密度を小さくすることができ、また流量(流速)も小さくできる。従って、図1及び2の実施例において、高比重水21を水底に放流するためのエネルギーを小さく抑え、最小限のエネルギーで広範囲に分散した底質1の汚染底質3を経済的・効率的に窪地6へ集めることができる。また、底質3中の粗粒分は搬送過程で沈降するが、細粒分の沈降速度は遅いので、ダイオキシン等の汚染物質が付着・吸着している細粒分を選択的に窪地6へ集めることができる。窪地6に集めた汚染底質粒子3は、窪地6を蓋材で被覆して封じ込めるか、窪地6から船上又は陸上に浚渫して処分するか、または適当な化学的・物理的・生物的処理により無害化することができる。   According to the present invention, the polluted bottom sediment 3 in the bottom 1 is transported to the depression 6 by the turbid water stream 12 whose density is increased by the bottom sediment 3 floating, so that the high-density water stream 10 before the bottom sediment 3 is suspended is not disturbed. The density can be reduced within a range in which diffusion of the bottom sediment 3 can be suppressed, and the flow rate (flow velocity) can also be reduced. Therefore, in the embodiment shown in FIGS. 1 and 2, the energy for discharging the high specific gravity water 21 to the bottom of the water is kept small, and the contaminated bottom sediment 3 of the bottom sediment 1 dispersed widely with the minimum energy is economical and efficient. Can be collected in the depression 6. In addition, the coarse particles in the bottom sediment 3 settle in the transport process, but the sedimentation rate of the fine particles is slow, so the fine particles to which contaminants such as dioxins adhere and adsorb are selectively transferred to the depression 6. Can be collected. Contaminated sediment particles 3 collected in the depressions 6 are covered with a cover material and sealed, or disposed on the ship or on land from the depressions 6 or by appropriate chemical / physical / biological treatment. Can be rendered harmless.

こうして本発明の目的である「広範囲に分布した汚染底質を経済的・効率的に処理できる水底汚染底質の処理方法」の提供を達成できる。   In this way, it is possible to achieve the object of the present invention, “a method for treating water-bottom contaminated sediment that can economically and efficiently treat polluted sediment distributed over a wide area”.

なお、図示例では高比重水21の放流により高密度水流10を形成しているが、本発明において高密度水流10の流量(流速)は小さくても足りるので、例えば放流管14を介してドライアイス等を水底1へ放流することにより水底1に高密度水塊を形成し、その高密度水塊の流れの中で水底1の底質3を撹乱することにより濁り水流12を形成することも可能である。この場合、先ず高密度水塊の窪地6に隣接する端縁側の底質3を撹乱して窪地6へ沈み込む密度流を形成し、次いで窪地6から離れた隣接部位の底質3を順次撹乱して密度を高めていくことにより、濁り水流12を窪地6へ誘導することができる。   In the illustrated example, the high-density water stream 10 is formed by the discharge of the high specific gravity water 21, but in the present invention, the flow rate (flow velocity) of the high-density water stream 10 may be small. A high density water mass is formed in the bottom 1 by discharging ice or the like to the bottom 1, and a turbid water flow 12 is formed by disturbing the sediment 3 of the bottom 1 in the flow of the high density water mass. Is possible. In this case, first, the bottom sediment 3 on the edge side adjacent to the depression 6 of the high-density water mass is disturbed to form a density flow that sinks into the depression 6, and then the bottom sediment 3 in the adjacent part away from the depression 6 is sequentially disturbed. By increasing the density, the muddy water stream 12 can be guided to the depression 6.

図3は、撹乱部材17として、高密度水流10により揺動可能な回転羽根17aを放流管14の下端に設けた本発明の実施例を示す。また図4は、高密度水流10により揺動可能な振動子17bを撹乱部材17とした実施例を示す。図示例の攪拌部材17は、高比重水21の放流により形成される高密度水流10により揺動し、水底1を撹乱する流れの乱れMを形成して底質3を高密度水流10中に浮遊させることができる。但し、攪拌部材17に外力を加えて水底1を撹乱してもよく、水流10の流速を高める向きに攪拌部材17を駆動することができる。濁り水流12は、流速が大きいほど底質3の搬送能力が高くなる。回転羽根17a及び振動子17bの揺動向きは図示例に限定されず、例えば回転羽根17aを水底1と対向させて下向きに設置し、回転羽根17aの周縁に水底1へ挿入可能な棒部材等を取り付け、回転羽根17a及び棒部材の回転により水底1の底質3を撹乱してもよい。   FIG. 3 shows an embodiment of the present invention in which a rotating blade 17 a that can be swung by the high-density water flow 10 is provided at the lower end of the discharge pipe 14 as the disturbing member 17. FIG. 4 shows an embodiment in which the vibrator 17 b that can be swung by the high-density water flow 10 is used as the disturbance member 17. The stirring member 17 in the illustrated example is swung by the high-density water stream 10 formed by the discharge of the high specific gravity water 21 to form a turbulence M that disturbs the bottom 1 to bring the sediment 3 into the high-density water stream 10. Can be floated. However, the water bottom 1 may be disturbed by applying an external force to the stirring member 17, and the stirring member 17 can be driven to increase the flow rate of the water flow 10. The turbid water stream 12 has a higher ability to convey the bottom sediment 3 as the flow velocity increases. The swinging direction of the rotary blade 17a and the vibrator 17b is not limited to the illustrated example. For example, a rod member or the like that can be inserted into the water bottom 1 at the periphery of the rotary blade 17a by placing the rotary blade 17a facing the water bottom 1 and facing downward. The bottom sediment 3 of the water bottom 1 may be disturbed by rotation of the rotary blade 17a and the rod member.

また図3及び図4の実施例では、放流管14の下端に高比重水21を水底1に沿って案内する底なし環状覆い15を接続し、撹乱部材17を環状覆い15の内側に設け、流れの乱れMによる高密度水流10と周囲の底層水との混合を環状覆い15により防止している。高密度水流10は、放流管14の下端から底なし環状覆い15の水平流路20内に放流されて撹乱部材17を揺動させ、撹乱部材17の揺動により撹乱された底質3と混合されて密度が高まり、濁り水流12として環状覆い15の出口から水底1に沿って放流される。但し、環状覆い15がない場合でも、撹乱部材17を放流管14の下端近傍に設けることにより、高密度水流10と周囲の底層水との混合を小さく抑えることは可能である。   3 and 4, a bottomless annular cover 15 for guiding the high specific gravity water 21 along the bottom 1 is connected to the lower end of the discharge pipe 14, and a disturbance member 17 is provided inside the annular cover 15. The annular cover 15 prevents the high-density water flow 10 and the surrounding bottom water from mixing due to the disturbance M. The high-density water flow 10 is discharged from the lower end of the discharge pipe 14 into the horizontal flow path 20 of the bottomless annular cover 15 to rock the disturbance member 17 and is mixed with the sediment 3 disturbed by the fluctuation of the disturbance member 17. As a result, the turbid water flow 12 is discharged along the bottom 1 from the outlet of the annular cover 15. However, even when the annular cover 15 is not provided, the mixing of the high-density water flow 10 and the surrounding bottom layer water can be kept small by providing the disturbance member 17 in the vicinity of the lower end of the discharge pipe 14.

更に図3及び図4の実施例では、底なし環状覆い15の出口に、撹乱部材17によって生じた流れの乱れMを整流Cとする整流化部材18を設けている。整流化部材18の一例は、撹乱部材17によって形成された流れの渦を消失する向きに取り付けた整流形成ベーンである。底質3と混合された濁り水流12を整流化部材18により整流化して放流することにより、放流後の濁り水流12からの底質3の拡散を最小限に抑えることができる。整流化しても、濁り水流12の密度は低下しないので、濁り水流12による底質3の搬送能力は保持できる。   Further, in the embodiment of FIGS. 3 and 4, a rectifying member 18 is provided at the outlet of the bottomless annular cover 15 so that the flow disturbance M generated by the disturbance member 17 is rectified C. An example of the flow straightening member 18 is a flow straightening vane that is attached in such a direction that the flow vortex formed by the disturbance member 17 disappears. By rectifying and discharging the turbid water stream 12 mixed with the bottom sediment 3 by the rectifying member 18, it is possible to minimize the diffusion of the bottom sediment 3 from the turbid water stream 12 after the discharge. Even if it rectifies | straightens, since the density of the muddy water stream 12 does not fall, the conveyance capability of the sediment 3 by the muddy water stream 12 can be maintained.

図5は、放流管14の下端の底なし環状覆い15の水平流路20を仕切板16によって上下2層の水平流路20a、20bに分け、下層流路20b内に撹乱部材17を設けて底質1を撹乱する本発明の実施例を示す。図示例では、攪拌部材17を仕切板16に固定した螺旋流誘導ベーンとし、下層流路20bの内側に流れの乱れM(この場合は、螺旋流)を形成して水底1を撹乱する。下層流路20b内に流入した高密度水流10は、撹乱された底質3と混合され、濁り水流12となって環状覆い15の出口から水底1に沿って放流される。他方、上層流路20a内に流入した高密度水流10は、そのまま整流Cとして環状覆い15の出口から放流される。この実施例では、下層流路20b内で生じた流れの乱れMを上層流路20a内の整流Cによって覆いつつ放流することにより、放流後の濁り水流12からの底質3の拡散を抑えている。必要に応じて、図示例の下層流路20bの出口に整流化部材18を設けてもよい。   FIG. 5 shows that the horizontal flow path 20 of the bottomless annular cover 15 at the lower end of the discharge pipe 14 is divided into two upper and lower horizontal flow paths 20a and 20b by a partition plate 16, and a disturbance member 17 is provided in the lower flow path 20b. 1 shows an embodiment of the present invention that disturbs quality 1; In the illustrated example, the stirring member 17 is a spiral flow induction vane fixed to the partition plate 16, and the turbulence M (in this case, a spiral flow) is formed inside the lower layer flow path 20b to disturb the water bottom 1. The high-density water flow 10 that has flowed into the lower layer flow path 20b is mixed with the disturbed bottom sediment 3 and becomes a turbid water flow 12, which is discharged along the water bottom 1 from the outlet of the annular cover 15. On the other hand, the high-density water flow 10 flowing into the upper layer flow path 20a is discharged from the outlet of the annular cover 15 as rectification C as it is. In this embodiment, the flow disturbance M generated in the lower layer flow path 20b is discharged while being covered by the rectification C in the upper layer flow path 20a, thereby suppressing the diffusion of the bottom sediment 3 from the turbid water flow 12 after the discharge. Yes. If necessary, a rectifying member 18 may be provided at the outlet of the lower layer flow path 20b in the illustrated example.

図6は、高密度水流10にマイクロバブル23を混入し、底質3の浮遊によりマイクロバブル23が混入した濁り水流12を形成する本発明の実施例を示す。マイクロバブルは微細な空気又は酸素の気泡であり、(1)気泡同士の合体や吸収が起こり難く、寿命が比較的長く、個別気泡のまま水中に長時間留まる、(2)水中の浮上速度が毎時2〜3mと極めて遅いため、水平方向の拡散性に優れている、(3)水中に長時間留まり、単位体積当たりの気泡表面積が大きいため、水に溶けやすい、(4)電気的に帯電しているため、水中浮遊物に対する吸着力を有する等の特徴が知られている。濁り水流12中にマイクロバブル23を混入することにより、浮遊させた底質3の沈降を抑え、濁り水流12の底層水に対する密度差を長時間維持することができる。とくに濁り水流12中の細粒分は、マイクロバブル23に電気的に吸着し得るので、マイクロバブル23により浮遊時間を延ばすことが期待できる。   FIG. 6 shows an embodiment of the present invention in which the microbubbles 23 are mixed in the high-density water stream 10 and the turbid water stream 12 mixed with the microbubbles 23 is formed by the floating of the bottom sediment 3. Microbubbles are fine air or oxygen bubbles. (1) It is difficult for bubbles to coalesce and absorb, has a relatively long life, and stays in water for a long time with individual bubbles. (2) Floating speed in water Since it is very slow at 2-3 meters per hour, it has excellent horizontal diffusivity. (3) It stays in water for a long time and has a large bubble surface area per unit volume, so it is easily dissolved in water. (4) Electrically charged Therefore, characteristics such as having an adsorptive power against suspended matters in water are known. By mixing the microbubbles 23 in the muddy water stream 12, the sedimentation of the suspended sediment 3 can be suppressed, and the density difference of the muddy water stream 12 from the bottom water can be maintained for a long time. In particular, since fine particles in the turbid water stream 12 can be electrically adsorbed to the microbubbles 23, it can be expected that the microbubbles 23 extend the floating time.

また、図6の実施例は、水底1の汚染底質3を集めて処理する場合だけでなく、嫌気化した水底1の汚染底質3の浄化への利用も期待できる。即ち、嫌気化した水底1に沿ってマイクロバブル23が混入した高密度水流10を形成しつつ水底1を撹乱して底質3を水流10中に浮遊させ、マイクロバブルが混入し且つ密度を高めた濁り水流12を水底1に沿って流動(例えば、窪地6へ向け流下)させることにより、水底1の広範囲に分散した汚染底質3に効率的に酸素を供給して浄化する。特許文献3の方法では、高密度高酸素濃度水を広範囲に供給するため大きな放流エネルギーが必要であった。これに対し図6の方法では、底質3の浮遊により濁り水流12の流速と掃流力を高めることができるので、高密度水10の放流エネルギーは比較的小さく抑えつつ、濁り水流12によってマイクロバブル23を遠くまで搬送し、掃流力により汚染底質3の表面を巻き上げながら効率的に酸素を供給できる。即ち、小さな放流エネルギーで広範囲に分散した汚染底質に効率的・経済的に酸素を供給して浄化することが期待できる。   In addition, the embodiment of FIG. 6 can be used not only for collecting and treating the contaminated sediment 3 of the water bottom 1 but also for purifying the contaminated sediment 3 of the anaerobic water bottom 1. That is, while forming the high-density water stream 10 mixed with microbubbles 23 along the anaerobic water bottom 1, the water bottom 1 is disturbed and the bottom sediment 3 is suspended in the water stream 10, and microbubbles are mixed and the density is increased. By flowing the turbid water stream 12 along the bottom 1 (for example, flowing toward the depression 6), oxygen is efficiently supplied to the contaminated sediment 3 dispersed in the bottom 1 to be purified. In the method of Patent Document 3, a large discharge energy is required to supply high density and high oxygen concentration water over a wide range. On the other hand, in the method of FIG. 6, the flow velocity and the scavenging force of the turbid water stream 12 can be increased by floating the bottom sediment 3, so that the discharge energy of the high-density water 10 is kept relatively small and the turbid water stream 12 Oxygen can be efficiently supplied while conveying the bubble 23 far and rolling up the surface of the contaminated sediment 3 by the scavenging force. That is, it can be expected to efficiently and economically supply and purify polluted sediment distributed over a wide area with small discharge energy.

本発明の一実施例の説明図である。It is explanatory drawing of one Example of this invention. 本発明の他の実施例の説明図である。It is explanatory drawing of the other Example of this invention. 本発明で用いる撹乱部材及び整流化部材の一例の説明図である。It is explanatory drawing of an example of the disturbance member and rectification | straightening member which are used by this invention. 本発明で用いる撹乱部材の他の一例の説明図である。It is explanatory drawing of another example of the disturbance member used by this invention. 本発明で用いる撹乱部材の更に他の一例の説明図である。It is explanatory drawing of another example of the disturbance member used by this invention. マイクロバブルを用いた本発明の実施例の説明図である。It is explanatory drawing of the Example of this invention using microbubble. 従来の水底汚染底質処分方法の一例の説明図である。It is explanatory drawing of an example of the conventional water bottom contaminated sediment disposal method. 図7の底質処分方法の原理を示す説明図である。It is explanatory drawing which shows the principle of the sediment disposal method of FIG.

符号の説明Explanation of symbols

1…水底 2…高密度底層水
3…汚染底質(底質粒子)
4…水面 5…汚染域
6…窪地 7…溝
10…高密度水流 12…濁り水流
14…放流管 15…環状覆い
16…上下仕切板 17…撹乱部材
17a…回転羽根 17b…振動子
17c…乱流誘導ベーン 18…整流化部材
20…水平流路 20a…上層(水平)流路
20b…下層(水平)流路 21…高比重水
23…マイクロバブル
B…マイクロバブルの浮揚力
L…沈降する密度流
M…撹乱流(乱流)
U…乗り上がる密度流
τ…掃流力
DESCRIPTION OF SYMBOLS 1 ... Water bottom 2 ... High density bottom water 3 ... Contaminated sediment (bottom particle)
4 ... water surface 5 ... contaminated area 6 ... depression 7 ... groove
10 ... High density water flow 12 ... Muddy water flow
14 ... Release pipe 15 ... Annular cover
16… Upper and lower partition plates 17… Disturbing members
17a… Rotating blade 17b… Vibrator
17c ... Turbulent induction vane 18 ... Rectification member
20 ... Horizontal channel 20a ... Upper (horizontal) channel
20b ... Lower layer (horizontal) channel 21 ... High specific gravity water
23 ... Microbubble B ... Microbubble levitation force L ... Density flow M ... Disturbance flow (turbulent flow)
U ... Riding density flow τ ... Scavenging force

Claims (11)

汚染された水底に沿って底層水より高密度の水流を水底の窪地へ向けて形成しつつ前記水底を撹乱して底質を前記水流中に浮遊させ、前記底質の浮遊により密度を高めた濁り水流により前記水底の汚染底質を窪地に集めて処理してなる水底汚染底質の処理方法。 The bottom was suspended in the water stream by disturbing the bottom while forming a water stream with higher density than the bottom water along the contaminated bottom, and the density was increased by floating the bottom. A method for treating water-bottom contaminated sediment, which is obtained by collecting and treating the polluted sediment from the bottom in a depression by turbid water flow. 請求項1の処理方法において、前記高密度水流にマイクロバブルを混入し、マイクロバブルにより前記浮遊させた底質の沈降を抑えてなる水底汚染底質の処理方法。 The processing method according to claim 1, wherein microbubbles are mixed in the high-density water flow, and sedimentation of the bottom sediment suspended by the microbubbles is suppressed. 汚染された水底に沿って底層水より高密度で且つマイクロバブルを混入した水流を形成しつつ前記水底を撹乱して底質を前記水流中に浮遊させ、前記底質の浮遊により密度を高めたマイクロバブル混入濁り水流により前記水底の汚染底質に酸素を供給して浄化してなる水底汚染底質の処理方法。 The bottom was suspended in the water stream by disturbing the bottom while forming a water stream that was denser than the bottom water and mixed with microbubbles along the contaminated bottom, and the density was increased by floating the bottom. A method for treating a bottom polluted bottom sediment obtained by supplying oxygen to the bottom polluted bottom sediment and purifying it by a turbid water stream mixed with microbubbles. 請求項1から3の何れかの処理方法において、前記高密度水流を下端が水底に開口する放流管経由で高比重水を水底に放流することにより形成してなる水底汚染底質の処理方法。 The processing method of the bottom polluted bottom sediment which forms in the processing method in any one of Claim 1 to 3 by discharging | emitting high specific gravity water to a water bottom through the discharge pipe which a lower end opens to a water bottom. 請求項4の処理方法において、前記放流管の下端に設けた撹乱部材により水底の底質を撹乱してなる水底汚染底質の処理方法。 5. The processing method according to claim 4, wherein the bottom sediment is disturbed by a disturbing member provided at a lower end of the discharge pipe. 請求項5の処理方法において、前記撹乱部材を高密度水流により揺動可能な回転羽根又は振動子としてなる水底汚染底質の処理方法。 6. The processing method according to claim 5, wherein the disturbing member is a rotating blade or vibrator that can be swung by a high-density water flow. 請求項5の処理方法において、前記撹乱部材を螺旋流誘導ベーンとしてなる水底汚染底質の処理方法。 6. The processing method according to claim 5, wherein the disturbing member is a spiral flow induction vane. 請求項4又は5の処理方法において、前記撹乱部材を外力により前記水流の流速を高める向きに駆動してなる水底汚染底質の処理方法。 6. The processing method according to claim 4 or 5, wherein the disturbing member is driven by an external force so as to increase the flow velocity of the water flow. 請求項5から8の何れかの処理方法において、前記放流管の下端に高比重水を水底に沿って案内する底なし環状覆いを接続し、前記撹乱部材を環状覆い内に設けてなる水底汚染底質の処理方法。 9. The bottom contaminated bottom according to claim 5, wherein a bottomless annular cover for guiding high specific gravity water along the bottom of the water is connected to a lower end of the discharge pipe, and the disturbance member is provided in the annular cover. Quality processing method. 請求項9の処理方法において、前記底なし環状覆いの出口に前記撹乱部材によって生じた流れの乱れを整流する整流化部材を設けてなる水底汚染底質の処理方法。 The processing method according to claim 9, wherein a rectifying member for rectifying a flow disturbance generated by the disturbance member is provided at an outlet of the bottomless annular cover. 請求項9の処理方法において、前記環状覆い内に仕切板により上下2層の流路を設け、下層流路内に撹乱部材を設けて底質を撹乱し、撹乱によって生じた下層流路内の流れの乱れを上層流路内の水流により覆いつつ放流してなる水底汚染底質の処理方法。 10. The processing method according to claim 9, wherein upper and lower two-layer flow paths are provided by a partition plate in the annular cover, a disturbing member is provided in the lower-layer flow path to disturb the bottom sediment, A method for treating bottom polluted sediment, wherein the disturbance of flow is covered by the water flow in the upper channel and discharged.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016032778A (en) * 2014-07-30 2016-03-10 国立研究開発法人産業技術総合研究所 Method for recovering soil particle adsorbate from environmental water region bottom part

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016032778A (en) * 2014-07-30 2016-03-10 国立研究開発法人産業技術総合研究所 Method for recovering soil particle adsorbate from environmental water region bottom part

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