JP7364350B2 - Sediment improvement method - Google Patents
Sediment improvement method Download PDFInfo
- Publication number
- JP7364350B2 JP7364350B2 JP2019061675A JP2019061675A JP7364350B2 JP 7364350 B2 JP7364350 B2 JP 7364350B2 JP 2019061675 A JP2019061675 A JP 2019061675A JP 2019061675 A JP2019061675 A JP 2019061675A JP 7364350 B2 JP7364350 B2 JP 7364350B2
- Authority
- JP
- Japan
- Prior art keywords
- soil
- sediment
- bottom sediment
- covering
- mixing
- 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.)
- Active
Links
- 239000013049 sediment Substances 0.000 title claims description 106
- 238000000034 method Methods 0.000 title claims description 64
- 239000002689 soil Substances 0.000 claims description 87
- 239000000203 mixture Substances 0.000 claims description 42
- 239000000463 material Substances 0.000 claims description 33
- 238000002156 mixing Methods 0.000 claims description 29
- 241000894006 Bacteria Species 0.000 claims description 25
- 239000008187 granular material Substances 0.000 claims description 25
- 239000000378 calcium silicate Substances 0.000 claims description 23
- 229910052918 calcium silicate Inorganic materials 0.000 claims description 23
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 claims description 23
- 239000000843 powder Substances 0.000 claims description 18
- 238000003756 stirring Methods 0.000 claims description 17
- 238000010276 construction Methods 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 241001148470 aerobic bacillus Species 0.000 claims description 12
- 239000013535 sea water Substances 0.000 claims description 8
- MKTRXTLKNXLULX-UHFFFAOYSA-P pentacalcium;dioxido(oxo)silane;hydron;tetrahydrate Chemical compound [H+].[H+].O.O.O.O.[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-][Si]([O-])=O.[O-][Si]([O-])=O.[O-][Si]([O-])=O.[O-][Si]([O-])=O.[O-][Si]([O-])=O.[O-][Si]([O-])=O MKTRXTLKNXLULX-UHFFFAOYSA-P 0.000 claims description 6
- 239000013505 freshwater Substances 0.000 claims description 4
- 239000002344 surface layer Substances 0.000 claims description 4
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 16
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 16
- 230000000052 comparative effect Effects 0.000 description 13
- 239000000126 substance Substances 0.000 description 13
- 239000010802 sludge Substances 0.000 description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 239000011575 calcium Substances 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 239000004576 sand Substances 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- 238000011065 in-situ storage Methods 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 3
- 230000001546 nitrifying effect Effects 0.000 description 3
- 230000033116 oxidation-reduction process Effects 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 239000010456 wollastonite Substances 0.000 description 3
- 229910052882 wollastonite Inorganic materials 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000001580 bacterial effect Effects 0.000 description 2
- 239000000292 calcium oxide Substances 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- UGGQKDBXXFIWJD-UHFFFAOYSA-N calcium;dihydroxy(oxo)silane;hydrate Chemical compound O.[Ca].O[Si](O)=O UGGQKDBXXFIWJD-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012851 eutrophication Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 210000003608 fece Anatomy 0.000 description 2
- 239000006028 limestone Substances 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 230000020477 pH reduction Effects 0.000 description 2
- 239000013618 particulate matter Substances 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 241000251468 Actinopterygii Species 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 101100382264 Mus musculus Ca14 gene Proteins 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000007481 next generation sequencing Methods 0.000 description 1
- 238000009828 non-uniform distribution Methods 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 238000001139 pH measurement Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 230000019086 sulfide ion homeostasis Effects 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 241001148471 unidentified anaerobic bacterium Species 0.000 description 1
- YKAIJSHGJPXTDY-CBDGTLMLSA-N α-cao Chemical group C([C@@H](N(CC1)C)C23C=CC4([C@H](C3)N(CCCl)CCCl)OC)C3=CC=C(O)C5=C3[C@@]21[C@H]4O5 YKAIJSHGJPXTDY-CBDGTLMLSA-N 0.000 description 1
Landscapes
- Treatment Of Sludge (AREA)
Description
本発明は、底質の改良方法に関する。 The present invention relates to a method for improving bottom sediment.
近年、日本近海において、富栄養化によって、有機質成分等を多く含むヘドロが干潟や海底に蓄積することが、社会問題となっている。
ヘドロが蓄積した海域では、底質から有機質成分、無機質成分等の栄養塩が溶出して、富栄養化がさらに進行し、赤潮が発生したり、あるいは、微生物による有機質成分の分解に伴って、底質中の酸素が消費されて嫌気状態となり、硫酸還元菌のような嫌気性微生物が増加して、硫化水素が発生するという問題がある。他にも、有機物由来の有機酸が生成して、底質が酸性化し、それに伴い、溶存態硫化物のうち、生態に対して毒性の強い遊離態の硫化水素が増加するなどの問題もある。それにより、生態系に悪影響が広がることが懸念されている。ここで、既往の研究において、硫化水素は、底質の表層の下方に形成された硫酸還元層から発生すると考えられている。
In recent years, eutrophication has caused the accumulation of sludge containing a large amount of organic matter on tidal flats and the seabed in the seas around Japan, which has become a social problem.
In sea areas where sludge has accumulated, nutrients such as organic and inorganic components are leached from the bottom sediment, eutrophication progresses further, red tide occurs, or as organic components are decomposed by microorganisms, The problem is that oxygen in the sediment is consumed and becomes anaerobic, and anaerobic microorganisms such as sulfate-reducing bacteria increase, producing hydrogen sulfide. Other problems include the production of organic acids derived from organic substances, which acidify the sediment, and the resulting increase in free hydrogen sulfide, which is highly toxic to the ecosystem, among dissolved sulfides. There are concerns that this will have a negative impact on the ecosystem. Here, in past research, it is believed that hydrogen sulfide is generated from a sulfuric acid reduction layer formed below the surface layer of sediment.
底質の改良方法として、底質を原位置で掘削および除去する方法である「浚渫」や、底質の上面を土砂やスラグ等で覆う方法である「覆砂」や、底質に石灰石、貝殻焼成物、水酸化マグネシウム等のアルカリ資材を散布して、底質に含まれている有機質成分をアルカリ分解する方法や、人力やトラクター等を用いて底質を撹拌して、嫌気状態である底質に空気を導入し、底質の一部（特にヘドロ）を分解して除去する方法である「耕耘」などが検討されている。 Methods for improving bottom sediment include dredging, which is a method of excavating and removing bottom sediment in situ, ``sand covering,'' which is a method of covering the top surface of the bottom sediment with sand, slag, etc., and adding limestone, limestone, etc. to the bottom sediment. Methods include spraying alkaline materials such as burned shells and magnesium hydroxide to alkali decompose the organic components contained in the sediment, or stirring the sediment using human power or tractors to create an anaerobic condition. ``Pilling,'' a method of introducing air into the bottom sediment to decompose and remove some of the bottom sediment (particularly sludge), is being considered.
特許文献１に、底質に含まれている成分に起因する、化学的酸素要求量の増大または硫化水素の発生を抑制するための、ケイ酸カルシウム含有粉粒状物（例えば、トバモライトを含む粉粒状物）からなる底質改善材が、記載されている。
また、特許文献１に、上記底質改善材を底質に散布する散布工程を含む底質の改善方法が、記載されている。
Patent Document 1 discloses that powder and granules containing calcium silicate (for example, powder and granules containing tobermorite) are used to suppress an increase in chemical oxygen demand or the generation of hydrogen sulfide caused by components contained in sediment. A bottom sediment improvement material consisting of
Furthermore, Patent Document 1 describes a method for improving bottom sediment, which includes a step of dispersing the above-mentioned bottom sediment improving material onto the bottom sediment.
本発明の目的は、好気性細菌等の割合を増大させて、ヘドロ（硫化水素等の有害物質を生じさせるもの）の生成を抑制することができ、かつ、原位置の生態系に悪影響を与えることがない、底質の改良方法を提供することである。 The purpose of the present invention is to increase the proportion of aerobic bacteria, etc., to suppress the production of sludge (which produces harmful substances such as hydrogen sulfide), and to suppress the production of sludge (which produces harmful substances such as hydrogen sulfide), which has a negative impact on the in-situ ecosystem. The purpose of the present invention is to provide a method for improving bottom sediment that never occurs before.
本発明者は、上記課題を解決するために鋭意検討した結果、底質を浚渫して、浚渫土を得た後、この浚渫土を、底質の原位置とは別の場所である、水域ではない作業場所に運搬し、次いで、この作業場所にて、浚渫土と、ケイ酸カルシウム含有粉粒状物からなる底質改良材を混合し撹拌して、覆土用混合物を得て、最後に、この覆土用混合物を底質の原位置に運搬して、覆土として用いれば、上記目的を達成しうることを見出し、本発明を完成した。 As a result of intensive studies to solve the above problems, the present inventors dredged the bottom sediment to obtain dredged soil, and then transferred the dredged soil to a water body in a location different from the original location of the bottom sediment. Then, at this work place, the dredged soil and a bottom sediment improvement material consisting of calcium silicate-containing powder and granules are mixed and stirred to obtain a soil covering mixture, and finally, The inventors have discovered that the above object can be achieved by transporting this soil covering mixture to the original location of the sediment and using it as covering soil, and have completed the present invention.
本発明は、以下の［１］～［４］を提供するものである。
［１］ 底質を浚渫して、浚渫土を得る浚渫工程と、上記浚渫土を、上記底質の原位置とは別の場所である、水域ではない作業場所に運搬する第一の運搬工程と、上記作業場所において、上記浚渫土と、ケイ酸カルシウム含有粉粒状物からなる底質改良材を混合し撹拌して、覆土用混合物を得る混合工程と、上記覆土用混合物を、上記底質の原位置に運搬する第二の運搬工程と、上記底質の原位置にて、上記覆土用混合物を覆土として用いる覆土施工工程、を含む底質の改良方法。
［２］ 上記混合工程における上記混合および撹拌は、上記覆土施工工程における上記覆土の施工時から４月間経過時までの間に上記覆土用混合物中の全細菌中の好気性細菌の割合が３％以上増大するような条件下にて、大気中で行われるものである、上記［１］に記載の底質の改良方法。
［３］ 上記ケイ酸カルシウム含有粉粒状物が、トバモライト、ゾノトライト、ＣＳＨゲル、フォシャジャイト、ジャイロライト、ヒレブランダイト、およびウォラストナイトからなる群より選ばれる１種以上を含む、上記［１］又は［２］に記載の底質の改良方法。
［４］ 上記混合工程において、上記底質改良材の量は、上記浚渫土１ｍ３当たり、０．１～５０ｋｇである、上記［１］～［３］のいずれかに記載の底質の改良方法。
The present invention provides the following [1] to [4].
[1] A dredging process in which bottom sediment is dredged to obtain dredged soil, and a first transportation process in which the dredged soil is transported to a work location that is different from the original location of the bottom sediment and is not in a water area. and a mixing step of mixing and stirring the dredged soil and a bottom sediment improvement material consisting of calcium silicate-containing powder and granules to obtain a mixture for covering soil at the work place; A method for improving bottom sediment, comprising: a second transporting step of transporting the bottom sediment to its original location; and a covering soil construction step using the above-mentioned soil covering mixture as covering soil at the original location of the bottom sediment.
[2] The above mixing and stirring in the above mixing step is performed until the proportion of aerobic bacteria in the total bacteria in the above soil covering mixture is 3% within 4 months from the time of construction of the above soil covering in the above soil covering construction step. The method for improving bottom sediment according to item [1] above, which is carried out in the atmosphere under conditions that increase the amount of sediment.
[3] The above [1], wherein the calcium silicate-containing powder or granular material contains one or more selected from the group consisting of tobermorite, xonotlite, CSH gel, foschagite, gyrolite, hillebrandite, and wollastonite. ] or the method for improving bottom sediment according to [2].
[4] The improvement of the bottom sediment according to any one of [1] to [ 3 ] above, wherein in the mixing step, the amount of the bottom sediment improvement material is 0.1 to 50 kg per 1 m 3 of the dredged soil. Method.
本発明の底質の改良方法によれば、好気性細菌の割合を増大させて、ヘドロの生成を抑制することができる。このため、ヘドロに起因する、硫化水素等の有害物質の発生を抑制することができる。
また、本発明の底質の改良方法によれば、硫黄酸化細菌の割合を増大させるので、硫化水素の発生を抑制することができる。
さらに、本発明の底質の改良方法によれば、覆土として、原位置の底質を改良したものを用いているので、覆砂として一般的に用いられている山砂や他所の海砂を用いる場合と異なり、周辺環境に負荷を与えることがなく、それゆえ、原位置の生態系に悪影響を与えることがない。
According to the method for improving sediment of the present invention, it is possible to increase the proportion of aerobic bacteria and suppress the production of sludge. Therefore, generation of harmful substances such as hydrogen sulfide caused by sludge can be suppressed.
Further, according to the method for improving bottom sediment of the present invention, since the proportion of sulfur-oxidizing bacteria is increased, the generation of hydrogen sulfide can be suppressed.
Furthermore, according to the method for improving bottom sediment of the present invention, improved in-situ bottom sediment is used as the covering soil, so mountain sand or sea sand from other places, which is commonly used as covering sand, can be used as the covering soil. Unlike when it is used, it does not place a burden on the surrounding environment, and therefore does not have a negative impact on the original ecosystem.
本発明の底質の改良方法は、底質を浚渫して、浚渫土を得る浚渫工程と、上記浚渫土を、上記底質の原位置とは別の場所である、水域ではない作業場所に運搬する第一の運搬工程と、上記作業場所において、上記浚渫土と、ケイ酸カルシウム含有粉粒状物からなる底質改良材を混合し撹拌して、覆土用混合物を得る混合工程と、上記覆土用混合物を、上記底質の原位置に運搬する第二の運搬工程と、上記底質の原位置にて、上記覆土用混合物を覆土として用いる覆土施工工程、を含む。
以下、本発明の底質の改良方法の各工程について、詳しく説明する。
The method for improving bottom sediment of the present invention includes a dredging step of dredging bottom sediment to obtain dredged soil, and transferring the dredged soil to a work site that is not a water area and is a location different from the original location of the bottom sediment. a first transportation step of transporting the soil, a mixing step of mixing and stirring the dredged soil with a bottom sediment improvement material consisting of calcium silicate-containing powder and granules at the work site to obtain a mixture for covering soil; The method includes a second transporting step of transporting the soil-covering mixture to the original location of the bottom sediment, and a soil-covering step of using the soil-covering mixture as covering soil at the bottom sediment location.
Each step of the method for improving bottom sediment of the present invention will be explained in detail below.
［浚渫工程］
浚渫工程は、底質を浚渫して、浚渫土を得る工程である。
本明細書中、「底質」とは、淡水、汽水または海水の水域において、水底を構成している表層をいう。
本発明の方法の処理対象である底質の好ましい一例としては、ヘドロを含むものが挙げられる。ヘドロを含む底質を処理対象とすることによって、本発明の効果（好気性細菌の割合を増大させて、ヘドロの生成を抑制することなど）をより効果的に得ることができる。
[Dredging process]
The dredging process is a process of dredging bottom sediment to obtain dredged soil.
As used herein, "sediment" refers to the surface layer constituting the bottom of a freshwater, brackish or seawater body of water.
A preferable example of the sediment to be treated in the method of the present invention includes sediment containing sludge. By treating bottom sediment containing sludge, the effects of the present invention (increasing the proportion of aerobic bacteria and suppressing sludge production, etc.) can be more effectively obtained.
［第一の運搬工程］
第一の運搬工程は、浚渫工程で得られた浚渫土を、浚渫工程における浚渫の対象である底質の原位置とは別の場所である、水域ではない作業場所に運搬する工程である。
本明細書中、「原位置」とは、浚渫工程における浚渫の対象である底質が存在していた位置（水底を構成する土砂の一部の領域）をいう。
本明細書中、「水域ではない作業場所」とは、後述の混合工程における混合および撹拌を行うための、淡水、汽水または海水が存在しない場所（特に、陸地に載置された、混合および撹拌を行うための混合槽）をいう。
浚渫土の運搬は、船舶、車両（例えば、トラック）等の任意の運搬手段を用いて行うことができる。
[First transportation process]
The first transportation process is a process of transporting the dredged soil obtained in the dredging process to a work site that is not a water body and is a place different from the original location of the sediment that is the target of dredging in the dredging process.
In this specification, the term "original position" refers to the position where the bottom sediment that is the target of dredging in the dredging process exists (a part of the area of the earth and sand that constitutes the water bottom).
In this specification, "a work place that is not a body of water" refers to a place where there is no fresh water, brackish water, or sea water for mixing and stirring in the mixing process described below (in particular, a place where mixing and stirring is carried out on land). mixing tank).
Transportation of the dredged soil can be performed using any transportation means such as a ship or a vehicle (for example, a truck).
［混合工程］
混合工程は、第一の運搬工程における浚渫土の運搬の目的地である作業場所において、浚渫土と、ケイ酸カルシウム含有粉粒状物からなる底質改良材を混合し撹拌して、覆土用混合物を得る工程である。
本発明で用いられるケイ酸カルシウム含有粉粒状物を構成する材料の例としては、トバモライト、ゾノトライト、ＣＳＨゲル、フォシャジャイト、ジャイロライト、ヒレブランダイト、ウォラストナイト等が挙げられる。
ここで、トバモライトとは、結晶性のケイ酸カルシウム水和物であり、Ｃａ５・（Ｓｉ６Ｏ１８Ｈ２）・４Ｈ2Ｏ（板状の形態）、Ｃａ５・（Ｓｉ６Ｏ１８Ｈ２）（板状の形態）、Ｃａ５・（Ｓｉ６Ｏ１８Ｈ２）・８Ｈ2Ｏ（繊維状の形態）等の化学組成を有するものである。
ゾノトライトとは、結晶性のケイ酸カルシウム水和物であり、Ｃａ６・（Ｓｉ６Ｏ１７）・（ＯＨ）2（繊維状の形態）等の化学組成を有するものである。
ＣＳＨゲルとは、αＣａＯ・βＳｉＯ2・γＨ2Ｏ（ただし、α／β＝０．７～２．３、γ／β＝１．２～２．７である。）の化学組成を有するものである。具体的には、３ＣａＯ・２ＳｉＯ2・３Ｈ2Ｏの化学組成を有するケイ酸カルシウム水和物等が挙げられる。
フォシャジャイトとは、Ｃａ４（ＳｉＯ３）３（ＯＨ）２等の化学組成を有するものである。
ジャイロライトとは、（ＮａＣａ２）Ｃａ１４（Ｓｉ２３Ａｌ）Ｏ６０（ＯＨ）８・１４Ｈ２Ｏ等の化学組成を有するものである。
ヒレブランダイトとは、Ｃａ２ＳｉＯ３（ＯＨ）２等の化学組成を有するものである。
ウォラストナイトとは、ＣａＯ・ＳｉＯ２（繊維状又は柱状の形態）等の化学組成を有するものである。
[Mixing process]
In the mixing step, dredged soil and a bottom sediment improvement material consisting of calcium silicate-containing powder and granules are mixed and stirred at the work site, which is the destination of transportation of the dredged soil in the first transportation step, to form a soil covering mixture. This is the process of obtaining
Examples of materials constituting the calcium silicate-containing granular material used in the present invention include tobermorite, xonotlite, CSH gel, foschagite, gyrolite, hillebrandite, and wollastonite.
Here, tobermorite is a crystalline calcium silicate hydrate, and includes Ca 5 · (Si 6 O 18 H 2 ) · 4H 2 O (plate-like form), Ca 5 · (Si 6 O 18 H 2 ) (plate-like form ), and has a chemical composition such as Ca5 .( Si6O18H2 ) .8H2O (fibrous form).
Zonotlite is a crystalline calcium silicate hydrate, and has a chemical composition such as Ca 6 .(Si 6 O 17 ).(OH) 2 (fibrous form).
CSH gel has a chemical composition of αCaO・βSiO 2・γH 2 O (α/β=0.7 to 2.3, γ/β=1.2 to 2.7). be. Specifically, calcium silicate hydrate having a chemical composition of 3CaO.2SiO 2 .3H 2 O and the like can be mentioned.
Foshagite has a chemical composition such as Ca 4 (SiO 3 ) 3 (OH) 2 .
Gyrolite has a chemical composition such as ( NaCa2 ) Ca14 ( Si23Al ) O60 (OH) 8.14H2O .
Hillebrandite has a chemical composition such as Ca 2 SiO 3 (OH) 2 .
Wollastonite has a chemical composition such as CaO.SiO 2 (fibrous or columnar form).
ケイ酸カルシウム含有粉粒状物は、好ましくは、多孔質のものである。この場合、ケイ酸カルシウム含有粉粒状物を含む覆土用混合物を、底質の原位置にて、覆土として用いると、ケイ酸カルシウム含有粉粒状物の多孔質の部分による通水性および通気性の確保、および、多孔質の部分に存在する空気によって、覆土の中の好気性細菌等の割合をより一層、増大させることができる。
本明細書中、「粉粒状物」とは、粉状物（０．１ｍｍ未満の粒度を有するもの）のみからなる集合体、粒状物（０．１ｍｍ以上の粒度を有するもの）のみからなる集合体、または、粉状物および粒状物を含む集合体を意味する。ここで、「粒度」とは、粉状物または粒状物における最大寸法（例えば、断面がだ円である粒状物においては、長軸の寸法）をいう。
The calcium silicate-containing powder or granule is preferably porous. In this case, if a soil covering mixture containing calcium silicate-containing powder and granules is used as a covering soil in situ on the bottom sediment, the porous portions of the calcium silicate-containing powder and granules ensure water permeability and air permeability. , and the air present in the porous parts can further increase the proportion of aerobic bacteria in the covered soil.
In this specification, "powder-like material" refers to an aggregate consisting only of powdery material (having a particle size of less than 0.1 mm), or an aggregate consisting only of granular material (having a particle size of 0.1 mm or more). means a body or an aggregate including powdery and granular materials. Here, "particle size" refers to the maximum dimension of a powder or granular material (for example, the dimension of the major axis in a granular material whose cross section is an ellipse).
ケイ酸カルシウム含有粉粒状物の粒度は、特に限定されないが、好ましくは、０．１～１０ｍｍの範囲内の粒状物の割合が８０質量％以上（特に、９０質量％以上）のものであり、より好ましくは、０．５～７ｍｍの範囲内の粒状物の割合が８０質量％以上（特に、９０質量％以上）のものであり、特に好ましくは、１～４ｍｍの範囲内の粒状物の割合が８０質量％以上（特に、９０質量％以上）のものである。
０．１～１０ｍｍの範囲内の粒状物の割合が８０質量％以上であれば、浚渫土と、ケイ酸カルシウム含有粉粒状物からなる底質改良材を混合し撹拌する際における粉塵の発生を抑制することができるとともに、粒度が過大であることによる問題（例えば、浚渫土の中のケイ酸カルシウム含有粉粒状物の分布が不均一になること）を回避することができる。
The particle size of the calcium silicate-containing powder or granules is not particularly limited, but preferably the proportion of granules in the range of 0.1 to 10 mm is 80% by mass or more (particularly 90% by mass or more), More preferably, the proportion of particulate matter within the range of 0.5 to 7 mm is 80% by mass or more (particularly 90% by mass or more), and particularly preferably the proportion of particulate matter within the range of 1 to 4 mm. is 80% by mass or more (particularly 90% by mass or more).
If the proportion of granules in the range of 0.1 to 10 mm is 80% by mass or more, dust generation is prevented when dredged soil and a sediment improver consisting of calcium silicate-containing powder and granules are mixed and stirred. At the same time, it is possible to avoid problems caused by excessive particle size (for example, non-uniform distribution of calcium silicate-containing powder and granules in dredged soil).
浚渫土と、ケイ酸カルシウム含有粉粒状物からなる底質改良材の混合および撹拌の方法の一例としては、混合槽（例えば、底面に撹拌翼を有する、上方のみが開口した金属製の枠体）の中に、浚渫土および底質改良材をこの順に投入して、混合物を得て、次いで、混合槽の撹拌手段（例えば、上述の撹拌翼）を回転させて、この混合物（浚渫土と底質改良材とからなるもの）を撹拌する方法が挙げられる。
本工程における混合および撹拌は、覆土施工工程における覆土の施工時から４月間経過時までの間に、覆土用混合物（覆土）中の全細菌中の好気性細菌の割合が３％以上増大するような条件下にて、大気中で行われることが好ましい。
ここで、「大気中」とは、混合および撹拌の過程で、浚渫土および底質改良材が、水中ではなく、空気に曝された状態に置かれることをいう。
また、本工程における混合および撹拌は、覆土施工工程における覆土の施工時から４月間経過時までの間に、覆土用混合物（覆土）中の全細菌中の硫黄酸化細菌の割合が１％以上（好ましくは２％以上、より好ましくは３％以上）増大するような条件下にて、大気中で行われることが好ましい。
上述の４月間で好気性細菌および硫黄酸化細菌の各割合を増大させるための条件としては、例えば、浚渫土の単位容積当たりの底質改良材の量を大きくしたり、あるいは、本工程（混合工程）における撹拌手段の回転速度や撹拌時間を調整（増大）することが挙げられる。
An example of a method for mixing and stirring dredged soil and a bottom sediment improvement material made of powder and granules containing calcium silicate is a mixing tank (for example, a metal frame with stirring blades on the bottom and an open top only). ), the dredged soil and the bottom sediment improvement material are put in this order to obtain a mixture, and then the stirring means (for example, the above-mentioned stirring blade) of the mixing tank is rotated to mix this mixture (the dredged soil and An example is a method of stirring a sediment improver.
The mixing and agitation in this process are performed so that the proportion of aerobic bacteria in the total bacteria in the soil covering mixture (covering soil) increases by 3% or more during the period of 4 months from the time of covering soil in the soil covering construction process. It is preferable to carry out the process in the atmosphere under suitable conditions.
Here, "in the atmosphere" means that during the mixing and stirring process, the dredged soil and the bottom sediment improvement material are exposed to the air rather than underwater.
In addition, the mixing and stirring in this process will ensure that the proportion of sulfur-oxidizing bacteria in the total bacteria in the soil-covering mixture (covering soil) is 1% or more ( It is preferable to carry out the process in the atmosphere under conditions such that the amount increases (preferably 2% or more, more preferably 3% or more).
Conditions for increasing the proportions of aerobic bacteria and sulfur-oxidizing bacteria during the four months mentioned above include, for example, increasing the amount of sediment improvement material per unit volume of dredged soil, or increasing the amount of sediment improving material in this process (mixing). An example of this is adjusting (increasing) the rotational speed and stirring time of the stirring means in step).
本工程において、底質改良材の量は、浚渫土１ｍ３当たり、好ましくは０．１～５０ｋｇ、より好ましくは０．３～４０ｋｇ、さらに好ましくは０．５～３０ｋｇ、さらに好ましくは１～２０ｋｇ、特に好ましくは２～１５ｋｇである。
該量が０．１ｋｇ以上であると、本発明の効果（好気性細菌の割合を増大させて、ヘドロの生成を抑制することなど）をより効果的に得ることができる。該量が５０ｋｇ以下であれば、底質改良材の量が大きいことによる本発明の方法のコストの増大を避けることができる。
In this step, the amount of the bottom sediment improver is preferably 0.1 to 50 kg, more preferably 0.3 to 40 kg, even more preferably 0.5 to 30 kg, and still more preferably 1 to 20 kg per 1 m 3 of dredged soil. , particularly preferably 2 to 15 kg.
When the amount is 0.1 kg or more, the effects of the present invention (increasing the proportion of aerobic bacteria and suppressing sludge production, etc.) can be more effectively obtained. If the amount is 50 kg or less, it is possible to avoid an increase in cost of the method of the present invention due to a large amount of bottom sediment improving material.
［第二の運搬工程］
第二の運搬工程は、混合工程で得られた覆土用混合物を、底質の原位置に運搬する工程である。
本工程において、底質の原位置への運搬とは、例えば、処理対象である底質が複数の区画に分かれている場合において、これら複数の区画の各々について、浚渫工程における浚渫土と、後工程である覆土施工工程における覆土用混合物とが一致（対応）している必要があるものではなく、これら複数の区画の中の区画Ａの浚渫土が、覆土用混合物としては、区画Ｂ（区画Ａとは異なる区画）に覆土されるものであってもよい。
覆土用混合物の運搬は、第一の運搬工程と同様に、船舶、車両（例えば、トラック）等の任意の運搬手段を用いて行うことができる。
[Second transportation process]
The second transportation step is a step of transporting the soil covering mixture obtained in the mixing step to the original location of the sediment.
In this process, transporting the sediment to its original location means, for example, when the sediment to be treated is divided into multiple compartments, the dredged soil in the dredging process and the It is not necessary to match (correspond) with the soil covering mixture in the soil covering construction process, but the dredged soil from section A among these multiple sections is used as the covering mixture for section B (section B). A section different from A) may be covered with soil.
The soil-covering mixture can be transported using any transport means such as a ship or a vehicle (for example, a truck), as in the first transport step.
［覆土施工工程］
覆土施工工程は、底質の原位置にて、覆土用混合物を覆土として用いる工程である。
本工程における「底質の原位置」とは、第二の運搬工程で説明した「底質の原位置への運搬」におけるものと同じである。
覆土の施工（敷設）は、通常、浚渫工程で浚渫された底質の厚さと同じ厚さになるように行われる。
覆土の施工によって、浚渫工程前の底質に比べて、好気性細菌の割合が増大するので、ヘドロの発生を抑制することができる。
また、覆土の施工によって、浚渫工程前の底質に比べて、硫黄酸化細菌（硫化水素を硫酸や元素状硫黄に酸化する細菌）の割合が増大するので、硫化水素による各種の生物の死滅を抑制し、また、硫化水素臭の発生を抑制することができる。
さらに、覆土の施工によって、浚渫工程前の底質に比べて、ｐＨが上昇するので、硝化細菌が増殖し易い環境をつくることができる。硝化細菌は、底質に生育する各種の生物の残餌や排泄物から生じる有害なアンモニアや亜硝酸を、無害な硝酸に分解する細菌である。
[Soil covering construction process]
The soil-covering construction process is a process in which a soil-covering mixture is used as a soil-covering soil in the original location of the sediment.
The "original position of the sediment" in this step is the same as that in "transportation of the sediment to the original location" explained in the second transportation step.
The construction (laying) of the soil cover is usually carried out so that it has the same thickness as the bottom sediment dredged during the dredging process.
The construction of soil covering increases the proportion of aerobic bacteria compared to the sediment before the dredging process, so it is possible to suppress the generation of sludge.
In addition, the construction of soil covering increases the proportion of sulfur-oxidizing bacteria (bacteria that oxidizes hydrogen sulfide to sulfuric acid and elemental sulfur) compared to the sediment before the dredging process, which prevents the death of various organisms due to hydrogen sulfide. It is also possible to suppress the generation of hydrogen sulfide odor.
Furthermore, the soil covering increases the pH compared to the bottom sediment before the dredging process, creating an environment in which nitrifying bacteria can easily proliferate. Nitrifying bacteria are bacteria that decompose harmful ammonia and nitrite, which are produced from the leftover food and excreta of various organisms that grow in sediment, into harmless nitric acid.
本工程において、覆土の施工時から１４日間経過後の時点におけるｐＨの上昇の幅は、好ましくは０．２、より好ましくは０．３、特に好ましくは０．４である。
覆土の施工の時期は、混合工程において浚渫土と底質改良材を混合し撹拌して覆土用混合物を得た直後（換言すると、混合工程の終了後に、第二の運搬工程を直ちに行い、覆土施工工程が実施可能になった時）でもよいし、あるいは、覆土用混合物を得た時点から数日間が経過した時などでもよい。
In this step, the range of increase in pH after 14 days has passed from the time of construction of the soil covering is preferably 0.2, more preferably 0.3, particularly preferably 0.4.
The time of construction for covering soil is immediately after the dredged soil and bottom sediment improvement material are mixed and stirred in the mixing process to obtain a mixture for covering soil (in other words, after the mixing process is completed, the second transportation process is immediately performed, and the soil covering is This may be the time when the construction process becomes feasible, or the time may be several days after obtaining the soil covering mixture.
以下、本発明を実施例により具体的に説明するが、本発明はこれらの実施例に限定されるものではない。
［覆土のｐＨの測定（実施例１～５、比較例１～２）］
（１）処理対象物（底質の一部）
処理対象物は、干潟の底質における厚さ２０ｃｍの部分（底質の上面から、その下方に２０ｃｍの深さまでの部分）とした。
処理対象物は、湿潤密度が１．９ｇ／ｃｍ３、含水率が２７％、ｐＨが７．１、酸化還元電位（ＯＲＰ）が７４ｍＶ、の各物性値を有するものであった。
（２）底質改良材
底質改良材であるケイ酸カルシウム含有粉粒状物としては、以下のとおり製造されたものを用いた。
まず、酸化カルシウム等のカルシウム源、珪石等のケイ酸源、および、水を混合してなるスラリーを鉄製の容器の中に収容した後、１８０℃、１０，０００ｈＰａの雰囲気下に、この容器（スラリーを収容した鉄製の容器）を置き、１０時間、水和反応を行った。次いで、この容器内の固形物を乾燥することによって、トバモライト（ケイ酸カルシウム含有物）からなる乾燥固形物を得た。得られた乾燥固形物を粉砕した後、得られた粉砕物を篩い分けして、粒度が１～４ｍｍのケイ酸カルシウム含有粉粒状物（底質改良材）を得た。
EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.
[Measurement of pH of covered soil (Examples 1 to 5, Comparative Examples 1 to 2)]
(1) Object to be treated (part of bottom sediment)
The object to be treated was a 20 cm thick portion of the bottom sediment of a tidal flat (a portion from the top surface of the bottom sediment to a depth of 20 cm below it).
The object to be treated had physical properties such as a wet density of 1.9 g/cm 3 , a water content of 27%, a pH of 7.1, and an oxidation-reduction potential (ORP) of 74 mV.
(2) Sediment improvement material As the calcium silicate-containing granular material as a sediment improvement material, one manufactured as follows was used.
First, a slurry made by mixing a calcium source such as calcium oxide, a silicic acid source such as silica stone, and water is placed in an iron container, and then the container ( A hydration reaction was carried out for 10 hours. Next, by drying the solid in this container, a dry solid consisting of tobermorite (calcium silicate-containing material) was obtained. After the obtained dry solid was pulverized, the obtained pulverized material was sieved to obtain calcium silicate-containing powder and granules (sediment improving material) having a particle size of 1 to 4 mm.
（３）覆土用混合物の調製および評価
大気中の雰囲気下において、底質０．６ｋｇに、底質１ｍ３当たり、表１に記載の量（単位：ｋｇ／ｍ３）の底質改良材を添加した後、得られた混合物を、ホバートミキサーで底質改良材が均一となるように撹拌（低速で１分３０秒の後、高速で１分３０秒）し、覆土用混合物（実施例１～５）を得た。
一方、比較例１として、底質のみからなり、かつ、撹拌しないものを用意した。
また、比較例２として、底質のみからなり、かつ、実施例１と同様に撹拌したものを用意した。
(3) Preparation and evaluation of mixture for covering soil In an atmospheric environment, apply the amount of sediment improving material listed in Table 1 (unit: kg/m 3 ) to 0.6 kg of sediment per 1 m 3 of sediment. After addition, the resulting mixture was stirred with a Hobart mixer so that the bottom sediment improver was uniform (1 minute 30 seconds at low speed, then 1 minute 30 seconds at high speed), and the mixture for covering soil (Example 1) ~5) was obtained.
On the other hand, as Comparative Example 1, one consisting only of bottom sediment and not stirred was prepared.
In addition, as Comparative Example 2, one consisting of only bottom sediment and stirred in the same manner as in Example 1 was prepared.
得られた覆土用混合物（比較例１～２では、底質）を２等分し、それぞれ合成樹脂製の容器（上方のみが開口したもの）に収容した後、これらの容器を、各々、水槽内の塩分濃度３％の人工海水中に完全に沈め、水槽に付属している空気供給管による曝気下で、４７日間、この人工海水中に置いた。
人工海水中に沈めた時点から、４７日間経過時までの間における覆土用混合物のｐＨを、表１に記載の各時点で測定した。
なお、人工海水は、７日間毎に１／３の量を新たなものに交換した。
結果を表１に示す。表１中の値は、覆土用混合物を２等分して収容した各容器のｐＨ値（２つ）の平均値である。
The obtained soil covering mixture (sediment in Comparative Examples 1 and 2) was divided into two equal parts and placed in synthetic resin containers (open only at the top), and each of these containers was placed in an aquarium. The fish were completely submerged in artificial seawater with a salinity of 3%, and kept in this artificial seawater for 47 days under aeration using an air supply pipe attached to the tank.
The pH of the soil covering mixture was measured at each time point listed in Table 1 from the time it was submerged in artificial seawater until 47 days had elapsed.
Note that 1/3 of the artificial seawater was replaced with fresh water every 7 days.
The results are shown in Table 1. The values in Table 1 are the average values of the pH values of each container (two) containing the soil covering mixture divided into two equal parts.
表１から、実施例１～５では、比較例１～２に比べて、時間の経過とともにｐＨが増大する傾向があり、底質改良材によって底質の酸性化を抑制しうることが確認された。
特に、実施例２～５では、７日間経過時以降のｐＨが７．５以上に維持されているので、硫化水素の発生の原因となる硫酸還元菌の増殖が抑制され、かつ、残餌や排泄物から生じる有害なアンモニアや亜硝酸を無害な硝酸に分解する硝化細菌が増殖し易い環境であることがわかった。
From Table 1, in Examples 1 to 5, the pH tends to increase over time compared to Comparative Examples 1 to 2, confirming that the sediment improving material can suppress acidification of the sediment. Ta.
In particular, in Examples 2 to 5, the pH after 7 days was maintained at 7.5 or higher, so the growth of sulfate-reducing bacteria, which causes hydrogen sulfide generation, was suppressed, and the remaining feed and It was found that the environment is conducive to the growth of nitrifying bacteria, which break down harmful ammonia and nitrite produced from excreta into harmless nitric acid.
［覆土の細菌叢の評価（実施例６、比較例３～４）］
（１）処理対象物（底質の一部）
実施例１と同じものを用いた。
（２）底質改良材
実施例１と同じものを用いた。
（３）覆土用混合物の調製および評価
実施例１と同様にして、覆土用混合物（実施例６）を得た。
一方、比較例３として、底質のみからなり、かつ、撹拌しないものを用意した。
また、比較例４として、底質のみからなり、かつ、実施例１と同様に撹拌したものを用意した。
実施例６および比較例３～４の各々の覆土用混合物を、覆土として、干潟の海水中に沈めた。４月間経過後に、底質の表層部分５ｃｍを採取し、得られた採取物について、細菌叢を次世代シークエンス解析によって評価した。また、採取時に採取場所にて、ｐＨおよび酸化還元電位（ＯＲＰ）を測定した。
結果を表２に示す。
[Evaluation of bacterial flora in covered soil (Example 6, Comparative Examples 3 to 4)]
(1) Object to be treated (part of bottom sediment)
The same material as in Example 1 was used.
(2) Bottom sediment improvement material The same material as in Example 1 was used.
(3) Preparation and evaluation of mixture for covering soil A mixture for covering soil (Example 6) was obtained in the same manner as in Example 1.
On the other hand, as Comparative Example 3, one consisting only of bottom sediment and not stirred was prepared.
In addition, as Comparative Example 4, one consisting of only bottom sediment and stirred in the same manner as in Example 1 was prepared.
The soil covering mixtures of Example 6 and Comparative Examples 3 and 4 were submerged in seawater in a tidal flat as soil covering. After 4 months, 5 cm of the surface layer of the sediment was collected, and the bacterial flora of the collected material was evaluated by next-generation sequencing analysis. In addition, pH and oxidation-reduction potential (ORP) were measured at the collection site at the time of collection.
The results are shown in Table 2.
表２から、実施例６では、比較例３～４に比べて、好気性細菌の割合が大きく、かつ、嫌気性細菌の割合が小さいことがわかる。
また、実施例６では、比較例３～４に比べて、硫黄酸化細菌の割合が大きいことがわかる。硫黄酸化細菌は、硫化水素（干潟の環境の悪化の原因となるもの）を硫酸や元素状硫黄に酸化する細菌であるので、硫黄酸化細菌の割合が大きいことは、有害な硫化水素の量が少なく、好ましい環境であることを意味する。一方、硫酸還元細菌および硫黄還元細菌は、硫化水素を生成する細菌であるので、硫酸還元細菌および硫黄還元細菌の割合が小さいことは、有害な硫化水素の量が少なく、好ましい環境であることを意味する。
なお、比較例３～４に比べて、実施例６における特殊な細菌の増加は、見られなかった。
また、実施例６では、比較例３～４に比べて、ｐＨおよびＯＲＰ（酸化還元電位）が大きいことがわかる。この理由は、ケイ酸カルシウム含有粉粒状物からなる底質改良材が、底質を好気性細菌の増加に適するように改良したからであると考えられる。
Table 2 shows that in Example 6, the proportion of aerobic bacteria is larger and the proportion of anaerobic bacteria is smaller than in Comparative Examples 3 and 4.
Furthermore, it can be seen that in Example 6, the proportion of sulfur-oxidizing bacteria is greater than in Comparative Examples 3 and 4. Sulfur-oxidizing bacteria are bacteria that oxidize hydrogen sulfide (which causes deterioration of the tidal flat environment) to sulfuric acid and elemental sulfur, so a large proportion of sulfur-oxidizing bacteria means that the amount of harmful hydrogen sulfide is It means a favorable environment. On the other hand, sulfate-reducing bacteria and sulfur-reducing bacteria are bacteria that produce hydrogen sulfide, so a small proportion of sulfate-reducing bacteria and sulfur-reducing bacteria indicates a favorable environment with a small amount of harmful hydrogen sulfide. means.
Note that, compared to Comparative Examples 3 and 4, no increase in the number of special bacteria was observed in Example 6.
Furthermore, it can be seen that in Example 6, the pH and ORP (oxidation-reduction potential) are higher than in Comparative Examples 3 and 4. The reason for this is thought to be that the bottom sediment improvement material made of powdery material containing calcium silicate improved the bottom sediment to be suitable for increasing the number of aerobic bacteria.
Claims (2)
上記浚渫土を、上記底質の原位置とは別の場所である、水域ではない作業場所に運搬する第一の運搬工程と、
上記作業場所において、上記浚渫土と、ケイ酸カルシウム含有粉粒状物からなる底質改良材を混合し撹拌して、覆土用混合物を得る混合工程と、
上記覆土用混合物を、上記底質の原位置に運搬する第二の運搬工程と、
上記底質の原位置にて、上記覆土用混合物を覆土として用いる覆土施工工程、
を含む底質の改良方法であって、
上記ケイ酸カルシウム含有粉粒状物が、トバモライトを含み、
上記混合工程において、上記底質改良材の量は、上記浚渫土１ｍ３当たり、２～５ｋｇである、底質の改良方法。 A dredging process for obtaining dredged soil by dredging bottom sediment, which is the surface layer constituting the water bottom, in a freshwater, brackish or seawater body of water;
A first transportation step of transporting the dredged soil to a work location that is different from the original location of the sediment and is not a water body;
A mixing step of mixing and stirring the dredged soil and a bottom sediment improvement material made of calcium silicate-containing powder and granules to obtain a soil-covering mixture at the work location;
a second transportation step of transporting the soil covering mixture to the original location of the sediment;
A soil covering construction process using the soil covering mixture as covering soil at the original location of the bottom sediment,
A method for improving bottom sediment, comprising:
The calcium silicate-containing powder or granular material contains tobermorite ,
In the mixing step, the amount of the bottom sediment improving material is 2 to 5 kg per 1 m 3 of the dredged soil.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019061675A JP7364350B2 (en) | 2019-03-27 | 2019-03-27 | Sediment improvement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019061675A JP7364350B2 (en) | 2019-03-27 | 2019-03-27 | Sediment improvement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2020157258A JP2020157258A (en) | 2020-10-01 |
| JP7364350B2 true JP7364350B2 (en) | 2023-10-18 |
Family
ID=72640947
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2019061675A Active JP7364350B2 (en) | 2019-03-27 | 2019-03-27 | Sediment improvement method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7364350B2 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003251397A (en) | 2002-03-04 | 2003-09-09 | Taguchi Gijutsu Kenkyusho:Kk | Treatment method for bottom materials |
| JP2012023986A (en) | 2010-07-21 | 2012-02-09 | Nippon Steel Corp | Method for inhibiting growth of algae |
| JP2016203107A (en) | 2015-04-24 | 2016-12-08 | 太平洋セメント株式会社 | Phosphorous recovery material, production method thereof, and phosphorous recovery method from wastewater containing phosphorous |
| JP2018051458A (en) | 2016-09-28 | 2018-04-05 | 太平洋セメント株式会社 | Sediment improving material and sediment improving method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60212297A (en) * | 1984-04-06 | 1985-10-24 | Sumitomo Kaiyo Kaihatsu Kk | Treatment of mud on bottom of water |
| JPH07251200A (en) * | 1994-03-14 | 1995-10-03 | Asahi Chem Ind Co Ltd | Treatment of sludge |
-
2019
- 2019-03-27 JP JP2019061675A patent/JP7364350B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003251397A (en) | 2002-03-04 | 2003-09-09 | Taguchi Gijutsu Kenkyusho:Kk | Treatment method for bottom materials |
| JP2012023986A (en) | 2010-07-21 | 2012-02-09 | Nippon Steel Corp | Method for inhibiting growth of algae |
| JP2016203107A (en) | 2015-04-24 | 2016-12-08 | 太平洋セメント株式会社 | Phosphorous recovery material, production method thereof, and phosphorous recovery method from wastewater containing phosphorous |
| JP2018051458A (en) | 2016-09-28 | 2018-04-05 | 太平洋セメント株式会社 | Sediment improving material and sediment improving method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2020157258A (en) | 2020-10-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4403095B2 (en) | Water environment conservation materials and methods of use | |
| JP2009297622A (en) | Water cleaning material | |
| JP2009045006A (en) | Hydrated solidified body for underwater installation | |
| JP6864452B2 (en) | Material for promoting algae growth | |
| CN111170597A (en) | In-situ substrate modifier | |
| JP2005144371A (en) | Bottom deposit modifying material | |
| JP6776080B2 (en) | Bottom sediment improvement material and bottom sediment improvement method | |
| JP2006257030A (en) | Mineral supplement for water area, alga reef block and method for producing the same | |
| KR101908972B1 (en) | Red tide and green algae removal agent for water purification and method for manufacturing thereof | |
| JP7364350B2 (en) | Sediment improvement method | |
| JPH0819774A (en) | Magnesia type modifier of water quality and bottom material | |
| JP6991726B2 (en) | Materials for promoting algae growth | |
| JP6812182B2 (en) | Material for promoting algae growth | |
| JP4474690B2 (en) | Porous stone for water purification and water purification method | |
| JP6052144B2 (en) | Civil engineering materials and methods for manufacturing the same | |
| JP6891844B2 (en) | Phosphorus supply materials for water bodies and their manufacturing methods | |
| JP2013215184A (en) | Civil engineering material for use in marine area | |
| JP7491605B2 (en) | Manufacturing method of spraying material for underwater greening and structure for installation in water area, and underwater greening construction method | |
| JP5627283B2 (en) | Treatment method of seabed sediment | |
| JP5168027B2 (en) | Repair method for steel revetment structures | |
| JP2007117069A (en) | Underwater animal and plant-proliferating body and marine ranch by utilizing the same | |
| KR20050024481A (en) | Depurator prepared using natural mineral powder containing germanium and method for preparing the same by preparing natural mineral powder, preparing quicklime, mixing natural mineral powder and quicklime and aging mixture | |
| JP7519198B2 (en) | Liquid for promoting algae growth and method for growing algae | |
| JP2000212564A (en) | Sea bottom soil-improving material and improvement of sea bottom soil | |
| JP7058486B2 (en) | Shellfish growth promoting material and method for promoting the growth of shellfish |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20220310 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20221226 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20230131 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20230327 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20230530 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20230824 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20230901 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20231003 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20231005 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7364350 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |