JP5665071B2 - Method for producing soil amendment for repairing contaminated soil containing fluorine, soil amendment, and method for repairing contaminated soil using the same - Google Patents
Method for producing soil amendment for repairing contaminated soil containing fluorine, soil amendment, and method for repairing contaminated soil using the same Download PDFInfo
- Publication number
- JP5665071B2 JP5665071B2 JP2009256318A JP2009256318A JP5665071B2 JP 5665071 B2 JP5665071 B2 JP 5665071B2 JP 2009256318 A JP2009256318 A JP 2009256318A JP 2009256318 A JP2009256318 A JP 2009256318A JP 5665071 B2 JP5665071 B2 JP 5665071B2
- Authority
- JP
- Japan
- Prior art keywords
- soil
- fluorine
- repairing
- contaminated soil
- volcanic ash
- 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
- 239000002689 soil Substances 0.000 title claims description 154
- 239000011737 fluorine Substances 0.000 title claims description 60
- 229910052731 fluorine Inorganic materials 0.000 title claims description 60
- 238000004519 manufacturing process Methods 0.000 title claims description 17
- 238000000034 method Methods 0.000 title claims description 11
- 239000002364 soil amendment Substances 0.000 title description 5
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 title 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 58
- 229910052602 gypsum Inorganic materials 0.000 claims description 44
- 239000010440 gypsum Substances 0.000 claims description 44
- ZOMBKNNSYQHRCA-UHFFFAOYSA-J calcium sulfate hemihydrate Chemical compound O.[Ca+2].[Ca+2].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O ZOMBKNNSYQHRCA-UHFFFAOYSA-J 0.000 claims description 39
- 239000000463 material Substances 0.000 claims description 36
- 239000002699 waste material Substances 0.000 claims description 31
- 230000006872 improvement Effects 0.000 claims description 30
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 13
- 239000000920 calcium hydroxide Substances 0.000 claims description 13
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 13
- 238000010438 heat treatment Methods 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 10
- 239000003516 soil conditioner Substances 0.000 claims description 10
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 claims description 9
- 238000003756 stirring Methods 0.000 claims description 8
- 238000010828 elution Methods 0.000 description 17
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 235000011116 calcium hydroxide Nutrition 0.000 description 12
- 238000007922 dissolution test Methods 0.000 description 6
- 239000005416 organic matter Substances 0.000 description 6
- 238000004064 recycling Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 230000002776 aggregation Effects 0.000 description 4
- 150000004683 dihydrates Chemical group 0.000 description 4
- 239000010802 sludge Substances 0.000 description 4
- 238000001179 sorption measurement Methods 0.000 description 4
- 229910001583 allophane Inorganic materials 0.000 description 3
- 239000011400 blast furnace cement Substances 0.000 description 3
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 3
- 229910001634 calcium fluoride Inorganic materials 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 150000001450 anions Chemical class 0.000 description 2
- 239000004927 clay Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 235000019700 dicalcium phosphate Nutrition 0.000 description 2
- 229910052587 fluorapatite Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000008439 repair process Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- FUFJGUQYACFECW-UHFFFAOYSA-L calcium hydrogenphosphate Chemical compound [Ca+2].OP([O-])([O-])=O FUFJGUQYACFECW-UHFFFAOYSA-L 0.000 description 1
- XAAHAAMILDNBPS-UHFFFAOYSA-L calcium hydrogenphosphate dihydrate Chemical compound O.O.[Ca+2].OP([O-])([O-])=O XAAHAAMILDNBPS-UHFFFAOYSA-L 0.000 description 1
- 239000002734 clay mineral Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- WMWXXXSCZVGQAR-UHFFFAOYSA-N dialuminum;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3] WMWXXXSCZVGQAR-UHFFFAOYSA-N 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 229910001653 ettringite Inorganic materials 0.000 description 1
- 229940077441 fluorapatite Drugs 0.000 description 1
- 150000002221 fluorine Chemical class 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- VSIIXMUUUJUKCM-UHFFFAOYSA-D pentacalcium;fluoride;triphosphate Chemical compound [F-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O VSIIXMUUUJUKCM-UHFFFAOYSA-D 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Landscapes
- Processing Of Solid Wastes (AREA)
- Soil Conditioners And Soil-Stabilizing Materials (AREA)
Description
本発明は、フッ素を含む汚染土壌を修復するための土壌改良材の製造方法および土壌改良材ならびにこれを用いた汚染土壌の修復方法に関する。 The present invention relates to a method of repairing a manufacturing method and soil conditioners, as well as contaminated soil using the same soil conditioner for repairing contaminated soil containing fluorine.
廃石膏ボードのリサイクルにおいては、石膏ボード中に含まれるフッ素の除去が問題となる。フッ素除去技術としては、水酸化カルシウムを加えてフッ化カルシウムとする方法が一般的である。しかしながら、フッ化カルシウムの溶解度は比較的高いため、土壌環境基準（０．８ｍｇ／Ｌ）のように非常に厳しい規制値まで下げるために、非特許文献１に記載のようにリン酸水素カルシウム二水和物を加えてフルオロアパタイト（フッ素燐灰石）を生成させる方法が開発されている。また、非特許文献２に記載のように高炉セメントＢ種を用いて生成するエトリンガイト内部にフッ素が取り込まれることが知られている。 In recycling waste gypsum board, removal of fluorine contained in gypsum board becomes a problem. As a fluorine removal technique, a method of adding calcium hydroxide to form calcium fluoride is common. However, since the solubility of calcium fluoride is relatively high, in order to lower it to a very strict regulation value as in the soil environment standard (0.8 mg / L), as described in Non-Patent Document 1, calcium hydrogen phosphate A method of adding hydrate to produce fluoroapatite (fluorapatite) has been developed. Further, as described in Non-Patent Document 2, it is known that fluorine is taken into ettringite produced using blast furnace cement B type.
しかしながら、リン酸水素カルシウム二水和物は高価であり、安定したフッ素の溶出防止のためには石膏への添加量を減らすことが難しい。そのため、非特許文献１に記載の方法はまだ事業化されていない。また、水酸化カルシウムを用いる方法は、前述のとおりフッ化カルシウムの溶解度が比較的高いため土壌環境基準をクリアできないほか、地盤改良材として用いた場合には改良後の土壌のｐＨが高く、盛土や埋め戻しなど利用先の地盤環境に悪影響を及ぼす恐れが指摘されている。さらに、非特許文献２に記載の高炉セメントＢ種の利用も水酸化カルシウムと同様に、強アルカリのため利用先の地盤環境面から問題がある。 However, calcium hydrogen phosphate dihydrate is expensive, and it is difficult to reduce the amount added to gypsum in order to prevent stable elution of fluorine. Therefore, the method described in Non-Patent Document 1 has not been commercialized yet. In addition, the method using calcium hydroxide cannot clear the soil environmental standards because the solubility of calcium fluoride is relatively high as described above, and when it is used as a ground improvement material, the pH of the soil after improvement is high, and the embankment It has been pointed out that it may adversely affect the ground environment of the user, such as backfilling and backfilling. Further, the use of the blast furnace cement B type described in Non-Patent Document 2 has a problem in terms of the ground environment of the use destination because of strong alkali like calcium hydroxide.
そこで、本発明では、廃石膏ボード等の廃石膏のリサイクルにおいて、石膏中に含まれているフッ素の溶出を防止し、フッ素を含む汚染土壌を修復することが可能な土壌改良材の製造方法および土壌改良材ならびにこれを用いた汚染土壌の修復方法を提供することを目的とする。 Therefore, in the present invention, in recycling of waste gypsum such as waste gypsum board, a method for producing a soil conditioner capable of preventing elution of fluorine contained in gypsum and repairing contaminated soil containing fluorine, and An object of the present invention is to provide a soil improvement material and a method for repairing contaminated soil using the same.
本発明の土壌改良材の製造方法は、粉砕された廃石膏を加熱脱水して得られた半水石膏に、火山灰土を混合攪拌する工程を含むことを特徴とする。これにより、廃石膏ボード等の廃石膏のリサイクルにおいて、粉砕された廃石膏を加熱脱水して得られた半水石膏に含まれるフッ素は、火山灰土の混合攪拌によって吸着および凝集され、溶出が防止される。そして、これにより得られた半水石膏と火山灰土とを含む土壌改良材は、フッ素を吸着および凝集することができるので、フッ素を含む汚染土壌に混合すると、汚染土壌中のフッ素を吸着および凝集し、フッ素の溶出を防止することができ、汚染土壌を修復することができる。 The method for producing a soil improvement material of the present invention includes a step of mixing and stirring volcanic ash soil with hemihydrate gypsum obtained by heating and dehydrating pulverized waste gypsum. As a result, in recycling waste gypsum such as waste gypsum board, fluorine contained in hemihydrate gypsum obtained by heating and dehydrating crushed waste gypsum is adsorbed and aggregated by mixing and stirring of volcanic ash soil, preventing elution Is done. And since the soil improvement material containing hemihydrate gypsum and volcanic ash soil thus obtained can adsorb and aggregate fluorine, when mixed with contaminated soil containing fluorine, it adsorbs and aggregates fluorine in contaminated soil. In addition, elution of fluorine can be prevented, and contaminated soil can be repaired.
なお、本発明に係る火山灰土とは、火山砕屑物（テフラ）を母材とする土壌をいい、土壌分類上では、腐植質火山灰土、黒色土、火山性黒色土、腐植質アロフェン土、黒ボク土や草原様褐色森林土などの名称で呼ばれるものである。 In addition, the volcanic ash soil according to the present invention refers to a soil based on volcanic debris (tephra), and in terms of soil classification, humic volcanic ash soil, black soil, volcanic black soil, humic allophane soil, It is called by the name of my soil or grassy brown forest soil.
ここで、火山灰土は乾燥または焼成したものであることが望ましい。火山灰土を乾燥することによって、火山灰土中の水分がなくなり、半水石膏と混合攪拌したときに火山灰土の保有水分が半水石膏と反応しない土壌改良材を製造することができる。また、火山灰土を焼成した場合には、火山灰土中の水分がなくなるとともに有機物が分解され、さらに加熱により滅菌されるので、土壌改良材を長期間保管しても、保管中に有機物が分解されることのない長期間安定な土壌改良材を製造することができる。 Here, it is desirable that the volcanic ash soil is dried or fired. By drying the volcanic ash soil, water in the volcanic ash soil is lost, and when the mixture is stirred with hemihydrate gypsum, a soil improvement material in which the retained moisture of the volcanic ash soil does not react with the hemihydrate gypsum can be produced. In addition, when volcanic ash soil is baked, moisture in the volcanic ash soil disappears and organic matter is decomposed and further sterilized by heating, so even if the soil conditioner is stored for a long time, the organic matter is decomposed during storage. It is possible to produce a soil improvement material that is stable for a long period of time.
また、火山灰土は半水石膏１００質量部に対して１０質量部以上であることが望ましい。火山灰土が焼成したものである場合には、火山灰土は半水石膏１００質量部に対して１０質量部以上であれば、フッ素溶出濃度が土壌環境基準０．８ｍｇ／Ｌ未満の土壌改良材を得ることができる。なお、火山灰土が乾燥したものである場合には、火山灰土は半水石膏１００質量部に対して３０質量部以上であれば、フッ素溶出濃度が土壌環境基準０．８ｍｇ／Ｌ未満の土壌改良材を得ることができる。 Moreover, as for volcanic ash soil, it is desirable that it is 10 mass parts or more with respect to 100 mass parts of hemihydrate gypsum. When the volcanic ash soil is fired, the volcanic ash soil is 10 parts by mass or more with respect to 100 parts by mass of hemihydrate gypsum. Can be obtained. In addition, when the volcanic ash soil is dried, if the volcanic ash soil is 30 parts by mass or more with respect to 100 parts by mass of hemihydrate gypsum, the soil improvement with a fluorine elution concentration of less than 0.8 mg / L of soil environment standard A material can be obtained.
さらに本発明の土壌改良材の製造方法では、硫酸アルミニウムまたは水酸化カルシウムを攪拌混合することが望ましい。これにより、火山灰土によるフッ素の吸着および凝集効果に加えて、硫酸アルミニウムまたは水酸化カルシウムによるフッ素の吸着および凝集がなされるため、よりフッ素の溶出が防止される。 Furthermore, in the method for producing a soil improving material of the present invention, it is desirable to stir and mix aluminum sulfate or calcium hydroxide. Thereby, in addition to the adsorption and aggregation effect of fluorine by volcanic ash soil, the adsorption and aggregation of fluorine by aluminum sulfate or calcium hydroxide are performed, so that the elution of fluorine is further prevented.
また、本発明の土壌改良材の製造方法は、廃石膏ボードを粉砕して紙と廃石膏とに分離し、廃石膏を加熱脱水する工程を含むことを特徴とする。廃石膏ボードを粉砕して紙と廃石膏とに分離し、この粉砕された廃石膏を加熱脱水して得られた半水石膏に、火山灰土を混合攪拌することで、廃石膏ボードから土壌改良材が得られる。 The method for producing a soil improvement material of the present invention includes a step of crushing waste gypsum board to separate it into paper and waste gypsum, and heat dehydrating the waste gypsum. The waste gypsum board is crushed and separated into paper and waste gypsum, and volcanic ash soil is mixed and stirred in the semi-water gypsum obtained by heating and dehydrating the crushed waste gypsum, thereby improving the soil from the waste gypsum board. A material is obtained.
（１）粉砕された廃石膏を加熱脱水して得られた半水石膏に、火山灰土を混合攪拌する工程を含む土壌改良材の製造方法により、半水石膏と火山灰土とを含む土壌改良材が得られる。この土壌改良材によれば、フッ素を吸着および凝集することができるので、フッ素を含む汚染土壌に混合すると、汚染土壌中のフッ素を吸着および凝集し、フッ素の溶出を防止することができ、汚染土壌を修復することができる。これにより、従来管理型最終処分場に埋立処分をしなければならなかった廃石膏ボード等の廃石膏のリサイクルを行うことが可能となる。 (1) A soil improvement material containing hemihydrate gypsum and volcanic ash soil by a method for producing a soil improvement material comprising a step of mixing and stirring volcanic ash soil with hemihydrate gypsum obtained by heating and dehydrating pulverized waste gypsum Is obtained. According to this soil amendment material, fluorine can be adsorbed and aggregated. Therefore, when mixed with contaminated soil containing fluorine, fluorine in the contaminated soil is adsorbed and aggregated, and elution of fluorine can be prevented. The soil can be repaired. This makes it possible to recycle waste gypsum such as waste gypsum board that had to be landfilled at a managed final disposal site .
（２）火山灰土が乾燥または焼成したものであることにより、水分や有機物を含まない土壌改良材、さらには加熱により滅菌された土壌改良材を製造することができ、長期間保管しても、保管中に有機物が分解されることのない長期間安定な土壌改良材が得られるという効果を奏することができる。 (2) Since the volcanic ash soil is dried or baked, it can produce soil amendments that do not contain moisture and organic matter, and even soil amendments that are sterilized by heating, The effect that the soil improvement material which is stable for a long time without an organic matter being decomposed | disassembled during storage can be obtained can be produced.
（３）さらに硫酸アルミニウムまたは水酸化カルシウムを攪拌混合することにより、火山灰土によるフッ素の吸着および凝集に加えて、硫酸アルミニウムまたは水酸化カルシウムによるフッ素の吸着および凝集がなされるため、よりフッ素の溶出が防止され、汚染土壌の修復効果がより高い土壌改良材が得られる。 (3) In addition to adsorbing and agglomerating fluorine by volcanic ash soil by mixing aluminum sulfate or calcium hydroxide with stirring, fluorine is adsorbed and agglomerated by aluminum sulfate or calcium hydroxide. And a soil improvement material with a higher effect of repairing contaminated soil can be obtained.
（４）廃石膏ボードを粉砕して紙と廃石膏とに分離し、この粉砕された廃石膏を加熱脱水して得られた半水石膏に、火山灰土を混合攪拌することで、廃石膏ボードから土壌改良材が得られる。 (4) Waste gypsum board is pulverized and separated into paper and waste gypsum, and volcanic ash soil is mixed and stirred into hemihydrate gypsum obtained by heating and dehydrating the pulverized waste gypsum. From the soil.
図１は本発明の実施の形態における土壌改良材の製造工程を示すフロー図である。
図１において、本発明の実施の形態における土壌改良材の製造方法では、まず廃石膏ボードを破砕し（Ｓ１１）、さらに粉砕した後（Ｓ１２）、紙と廃石膏とに分離する（Ｓ１３）。石膏ボードは、２枚の紙の間に半水石膏に水を加えて練ったものを流し込み、板状に固化されて製造されるものであり、紙は分別することで容易にリサイクルや焼却等で処分することが可能である。
FIG. 1 is a flowchart showing a manufacturing process of a soil improvement material in an embodiment of the present invention.
In FIG. 1, in the manufacturing method of the soil improvement material in embodiment of this invention, a waste gypsum board is first crushed (S11), and after further crushing (S12), it isolate | separates into paper and waste gypsum (S13). Gypsum board is produced by adding water and kneaded half-water gypsum between two sheets of paper, solidified into a plate, and can be easily recycled or incinerated by separating the paper. Can be disposed of.
次に、この粉砕された廃石膏を加熱脱水して半水石膏を得る（Ｓ１４）。石膏ボードに使用されている石膏は、２分子の結晶水を持つ二水石膏（ＣａＳＯ４・２Ｈ２Ｏ）である。この二水石膏は１２０〜１５０℃で加熱すると、結晶水の３／４を失って半水石膏（ＣａＳＯ４・１／２Ｈ２Ｏ）に変わる。この半水石膏は、水を加えて混練し、放置すると、水和反応を起こして、再び元の二水石膏に戻って固まる性質を持っている。 Next, the ground waste gypsum is heated and dehydrated to obtain hemihydrate gypsum (S14). The gypsum used for the gypsum board is dihydrate gypsum (CaSO 4 .2H 2 O) having two molecules of crystal water. When this dihydrate gypsum is heated at 120 to 150 ° C., it loses 3/4 of crystal water and changes to hemihydrate gypsum (CaSO 4 · 1 / 2H 2 O). This hemihydrate gypsum has the property of adding water, kneading, and leaving it to stand, causing a hydration reaction, and then returning to the original dihydrate gypsum and solidifying.
一方、黒ボク土は乾燥もしくは焼成して（Ｓ１５）、この半水石膏に混合攪拌する（Ｓ１６）。半水石膏中にはフッ素が１５００ｍｇ／ｋｇ程度含まれるが、このフッ素は黒ボク土によって吸着および凝集される。黒ボク土には活性アルミニウム、粘土鉱物であるアロフェン（二酸化ケイ素・酸化アルミニウムの水和物）やイモゴライト等が多く含まれており、これらはリン酸などの陰イオンも多く多量に吸着する性質を有する。そのため、同じく陰イオンであるフッ素も同様に吸着し、結合することで、フッ素が不溶化される。これにより、フッ素の溶出が防止された土壌改良材が得られる。 On the other hand, the black soil is dried or fired (S15), and mixed and stirred in this hemihydrate gypsum (S16). The hemihydrate gypsum contains about 1500 mg / kg of fluorine, and this fluorine is adsorbed and aggregated by the black soil. Black soil contains a lot of active aluminum, clay minerals allophane (silicon dioxide / aluminum oxide hydrate), imogolite, etc., and these adsorb a lot of anions such as phosphoric acid. Have. Therefore, fluorine, which is also an anion, is similarly adsorbed and bonded, thereby insolubilizing the fluorine. Thereby, the soil improvement material in which the elution of fluorine was prevented is obtained.
以上のように、半水石膏に乾燥もしくは焼成黒ボク土を混合攪拌することで、半水石膏に含まれるフッ素の溶出が防止され、汚染土壌の土壌改良材として使用することが可能となる。この土壌改良材は、さらにフッ素を吸着および凝集することができるため、無機性汚泥、土壌やヘドロ等のフッ素で汚染された汚染土壌に混合すると、汚染土壌中のフッ素を吸着および凝集するようになり、フッ素の溶出を防止することができる。したがって、この土壌改良材により汚染土壌を修復することが可能である。 As described above, by mixing and stirring dry or calcined black soil with hemihydrate gypsum, elution of fluorine contained in the hemihydrate gypsum is prevented, and it can be used as a soil improvement material for contaminated soil. Since this soil conditioner can further adsorb and aggregate fluorine, when mixed with contaminated soil contaminated with fluorine, such as inorganic sludge, soil and sludge, it adsorbs and aggregates fluorine in contaminated soil. Thus, elution of fluorine can be prevented. Therefore, it is possible to repair contaminated soil with this soil improvement material .
なお、本実施形態においては、火山灰土として黒ボク土を使用しているが、土壌分類上、腐植質火山灰土、黒色土、火山性黒色土、腐植質アロフェン土、黒ボク土や草原様褐色森林土などの名称で呼ばれる他の火山灰土についても同様に使用することが可能である。 In addition, in this embodiment, I use black soil as volcanic ash soil, but for the soil classification, humic volcanic ash soil, black soil, volcanic black soil, humic allophane soil, black soil and grass-like brown. Other volcanic ash soils called forest soils can be used in the same way.
また、本実施形態においては、乾燥もしくは焼成した黒ボク土を半水石膏に混合攪拌している。焼成した黒ボク土を混合した土壌改良材では、黒ボク土中の水分がなくなるとともに有機物が分解され、かつ加熱により滅菌されているので、土壌改良材を長期間保管しても、保管中に有機物が分解されることがなく、長期間安定である。一方、乾燥した黒ボク土では、黒ボク土中の水分がなくなり、半水石膏と混合攪拌したときに黒ボク土の保有水分が半水石膏と反応しないという安定性がある。なお、焼成も乾燥もしない黒ボク土では、半水石膏と黒ボク土を混合したときに、自然状態での黒ボク土が保有している水分と半水石膏が反応して二水石膏に戻ってしまい、汚染土壌の水分の吸収ならびに半水石膏の特徴の一つである固化作用が期待できなくなる。 In this embodiment, dried or baked black soil is mixed and stirred in hemihydrate gypsum. In the soil improvement material mixed with baked black soil, the water content in the black soil is lost and the organic matter is decomposed and sterilized by heating. Organic matter is not decomposed and is stable for a long time. On the other hand, the dried black soil has stability that the water in the black soil disappears and the retained water of the black soil does not react with the hemihydrate gypsum when mixed with the hemihydrate gypsum. In the case of black soil that is neither fired nor dried, when water is mixed with hemihydrate gypsum and water, the water content of the natural black soil and the half water gypsum react to form dihydrate gypsum. As a result, the water absorption of the contaminated soil and the solidification action that is one of the characteristics of hemihydrate gypsum cannot be expected.
また、前述の黒ボク土に加えて、さらに硫酸アルミニウムまたは水酸化カルシウムを攪拌混合することにより、土壌改良材を製造することも可能である。これにより、火山灰土によるフッ素の吸着および凝集効果に加えて、硫酸アルミニウムまたは水酸化カルシウムによるフッ素の吸着および凝集がなされるため、よりフッ素の溶出が防止され、汚染土壌の修復効果がより高い土壌改良材が得られる。 Moreover, in addition to the above-mentioned black soil, it is also possible to produce a soil improving material by further stirring and mixing aluminum sulfate or calcium hydroxide. As a result, in addition to the adsorption and agglomeration effect of fluorine by volcanic ash soil, the adsorption and agglomeration of fluorine by aluminum sulfate or calcium hydroxide are performed, so that the elution of fluorine is further prevented and the soil has a higher effect of repairing contaminated soil. An improved material is obtained.
以下、本発明を実験結果に基づいて説明する。試験用の試料（サンプル）は、次のようにして作成した。
（１）試料番号１は、半水石膏それ自体を溶出試験用サンプルとした。
（２）試料番号２〜４の乾燥黒ボク土は、雨の振込みを防止した屋内で自然乾燥（風乾）した後、粉砕して所定量の半水石膏と混合し、これを溶出試験用サンプルとした。
（３）試料番号５〜７の乾燥黒ボク土は、３５０℃の乾燥キルンを用いて焼成した後、粉砕して所定量の半水石膏と混合し、これを溶出試験用サンプルとした。
（４）試料番号８は、半水石膏に所定量の消石灰を混合し、これを溶出試験用サンプルとした。
（５）試料番号９は、半水石膏に所定量の乾燥黒ボク土および硫酸アルミニウムを混合し、これを溶出試験用サンプルとした。
なお、試験用のいずれの試料（サンプル）も、半水石膏と混合した後、チャック付ポリ袋に入れ、室温で１４日間養生した資料を溶出試験に用いた。また、溶出試験方法は環境庁告示第４６号に準拠して行った。
Hereinafter, the present invention will be described based on experimental results. A test sample (sample) was prepared as follows.
(1) For sample No. 1, hemihydrate gypsum itself was used as a sample for dissolution test.
(2) The dry black soil of sample numbers 2 to 4 is naturally dried (air-dried) indoors in a rain-prevented environment, then pulverized and mixed with a predetermined amount of hemihydrate gypsum, and this is a sample for dissolution test. It was.
(3) The dry black soil of sample numbers 5 to 7 was fired using a dry kiln at 350 ° C., pulverized and mixed with a predetermined amount of hemihydrate gypsum, and this was used as a sample for dissolution test.
(4) For sample number 8, a predetermined amount of slaked lime was mixed with hemihydrate gypsum, and this was used as a sample for dissolution test.
(5) For sample number 9, a predetermined amount of dry black clay and aluminum sulfate were mixed in hemihydrate gypsum, and this was used as a sample for dissolution test.
All samples for testing (samples) were mixed with hemihydrate gypsum, placed in a plastic bag with a chuck, and cured for 14 days at room temperature. In addition, the dissolution test method was performed in accordance with Notification No. 46 of the Environment Agency.
表１に実験結果を示す。
表１から以下のことがわかる。
（１）半水石膏それ自体からは、土壌環境基準（０．８ｍｇ／Ｌ）を超えるフッ素の溶出が確認された（試料番号１）。
（２）乾燥黒ボク土では、半水石膏１００部に対して３０部を加えることでフッ素溶出濃度は土壌環境基準０．８ｍｇ／Ｌ以下になった（試料番号４）。したがって、半水石膏１００部に対して乾燥黒ボク土３０部以上を加えることで、フッ素溶出濃度を土壌環境基準０．８ｍｇ／Ｌ以下とすることが可能であると思われる。
（３）焼成黒ボク土では、半水石膏１００部に対して１０部以上を加えることでフッ素溶出濃度は土壌環境基準０．８ｍｇ／Ｌ以下になった（試料番号５〜７）。
（４）既往の技術である消石灰１０部を加えた試験では、フッ素溶出濃度は土壌環境基準を超えることが確認されたばかりでなく、ｐＨが１２．９と高い値であった。この場合、自然環境に及ぼす影響が懸念される（試料番号８）。
（５）半水石膏に乾燥黒ボク土および硫酸アルミニウムを加えたサンプルでは、フッ素溶出濃度は土壌環境基準０．８ｍｇ／Ｌ以下であった（試料番号９）。
（６）既往の技術である消石灰１０部を加えた試料（試料番号８）のｐＨは強アルカリ性を示しているのに対し、乾燥黒ボク土および焼成黒ボク土を混合した試料（試料番号２〜７）の溶出液のｐＨは、いずれも中性を示している。このことから、本発明の土壌改良材は、汚染土壌の浄化材として利用しても、利用先の土壌のｐＨを上昇させない、すなわち自然に優しい土壌改良材といえる。
Table 1 shows the following.
(1) From hemihydrate gypsum itself, elution of fluorine exceeding the soil environmental standard (0.8 mg / L) was confirmed (Sample No. 1).
(2) In the dry black soil, the fluorine elution concentration became 0.8 mg / L or less of soil environment standard by adding 30 parts to 100 parts of hemihydrate gypsum (sample number 4). Therefore, by adding 30 parts or more of dry black soil to 100 parts of hemihydrate gypsum, it seems that the fluorine elution concentration can be reduced to 0.8 mg / L or less of the soil environment standard.
(3) In the burnt black soil, by adding 10 parts or more to 100 parts of hemihydrate gypsum, the fluorine elution concentration became 0.8 mg / L or less of the soil environment standard (sample numbers 5 to 7).
(4) In a test in which 10 parts of slaked lime, which is a conventional technique, was added, it was confirmed that the fluorine elution concentration exceeded the soil environmental standard, and the pH was a high value of 12.9. In this case, there is a concern about the influence on the natural environment (Sample No. 8).
(5) In the sample obtained by adding dry black clay and aluminum sulfate to hemihydrate gypsum, the fluorine elution concentration was 0.8 mg / L or less of the soil environment standard (Sample No. 9).
(6) While the pH of the sample (sample No. 8) added with 10 parts of slaked lime, which is a conventional technique, shows strong alkalinity, the sample (sample No. 2) mixed with dried black baked earth and baked black earth The pH of the eluate of ˜7) is neutral. From this, even if it uses as a purification material of contaminated soil, the soil improvement material of this invention can be said to be a soil improvement material which does not raise the pH of the soil of a utilization place, ie, is natural.
本発明の土壌改良材は、無機性汚泥、土壌やヘドロ等のフッ素で汚染された土壌の修復に用いることのできる土壌改良材として有用である。
Soil improvement material of the present invention are useful as inorganic sludge, soil conditioner that can be used in repair of soil contaminated with fluorine, such as soil or sludge.
Claims (11)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009256318A JP5665071B2 (en) | 2009-11-09 | 2009-11-09 | Method for producing soil amendment for repairing contaminated soil containing fluorine, soil amendment, and method for repairing contaminated soil using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009256318A JP5665071B2 (en) | 2009-11-09 | 2009-11-09 | Method for producing soil amendment for repairing contaminated soil containing fluorine, soil amendment, and method for repairing contaminated soil using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2011099079A JP2011099079A (en) | 2011-05-19 |
| JP5665071B2 true JP5665071B2 (en) | 2015-02-04 |
Family
ID=44190526
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009256318A Active JP5665071B2 (en) | 2009-11-09 | 2009-11-09 | Method for producing soil amendment for repairing contaminated soil containing fluorine, soil amendment, and method for repairing contaminated soil using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5665071B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2868518C (en) | 2012-03-30 | 2018-11-27 | Masato Yamaguchi | Insolubilizing agent for specific toxic substances, method for insolubilizing specific toxic substances using same, and soil improving method |
| JP6227267B2 (en) * | 2012-03-30 | 2017-11-08 | 吉野石膏株式会社 | Insolubilizing and solidifying material for specific harmful substances containing gypsum and method for improving soil using the same |
| CN105414163B (en) * | 2015-11-09 | 2019-08-02 | 四川龙蟒钛业股份有限公司 | A kind of method of cadmium pollution soil repair |
| JP6559551B2 (en) * | 2015-11-18 | 2019-08-14 | 株式会社トクヤマ | Method for producing dihydrate gypsum with reduced fluorine elution |
| KR101967732B1 (en) * | 2017-04-13 | 2019-04-10 | 정기용 | Manufacturing method of soil conditioner |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001122645A (en) * | 1999-10-27 | 2001-05-08 | Sumitomo Osaka Cement Co Ltd | Production process of regenerated hemihydrate gypsum and production process of soil solidification agent |
| JP4392514B2 (en) * | 2002-10-17 | 2010-01-06 | 学校法人日本大学 | Carbide-containing gypsum cured body and method for producing the same |
| JP2006263509A (en) * | 2005-03-22 | 2006-10-05 | Chugoku Electric Power Co Inc:The | Method for fixing substance easily eluted in water, and material obtained by it |
| JP2008094901A (en) * | 2006-10-10 | 2008-04-24 | Asahi Organic Chem Ind Co Ltd | Mud solidifying material |
| JP5656139B2 (en) * | 2008-03-05 | 2015-01-21 | 積水化学工業株式会社 | Ground improvement soil and ground improvement method |
| WO2009128490A1 (en) * | 2008-04-16 | 2009-10-22 | 株式会社Azmec | Insolubilizing agent for toxic substances, method for insolubilization of toxic substances, and water treatment process |
-
2009
- 2009-11-09 JP JP2009256318A patent/JP5665071B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2011099079A (en) | 2011-05-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jayaranjan et al. | Reuse options for coal fired power plant bottom ash and fly ash | |
| Pan et al. | Stabilization/solidification characteristics of organic clay contaminated by lead when using cement | |
| Pourakbar et al. | Stabilization of clayey soil using ultrafine palm oil fuel ash (POFA) and cement | |
| Jianli et al. | Effect of magnesium oxychloride cement on stabilization/solidification of sewage sludge | |
| JP2014057949A (en) | Treatment method of pollution type waste gypsum and non-pollution type gypsum composition | |
| CN102897992B (en) | Method for solidifying and stabilizing sludge from urban sewage treatment plant | |
| JP5665071B2 (en) | Method for producing soil amendment for repairing contaminated soil containing fluorine, soil amendment, and method for repairing contaminated soil using the same | |
| Cherian et al. | Engineering and environmental evaluation for utilization of recycled pulp mill fly ash as binder in sustainable road construction | |
| CN105753279B (en) | A kind of silt/sludge solidifying agent and its application method | |
| Li et al. | Dynamic leaching behavior of geogenic As in soils after cement-based stabilization/solidification | |
| JP2018126683A (en) | Phosphorus adsorbent, and method for producing the same | |
| CN108672482A (en) | One heavy metal species fixative and heavy-metal contaminated soil curing | |
| CN104128363A (en) | Method for repairing cadmium-polluted soil by crosslinking agent structure-modified algae | |
| Zhu et al. | The effect of simulated acid rain on the stabilization of cadmium in contaminated agricultural soils treated with stabilizing agents | |
| KR101235251B1 (en) | Cement using waterworks sludge and mathod for manufacturing the same | |
| Damrongsiri | Feasibility of using demolition waste as an alternative heavy metal immobilising agent | |
| Peng et al. | Sludge aging stabilizes heavy metals subjected to pyrolysis | |
| JP4694434B2 (en) | By-product processing method | |
| CN108298854B (en) | Sludge solidification/stabilization curing agent and preparation method and application thereof | |
| JP2009028639A (en) | Sludge treatment method | |
| KR101640160B1 (en) | Method for preparing a hardening composition for deep mixing method and hardening composition for deep mixing method | |
| Samuel | Synthesis of metakaolin-based geopolymer and its performance as sole stabilizer of expansive soils | |
| KR101346070B1 (en) | Recycling Soil and Recycling Soil Manufacturing Method, Utilizing Organic and Inorganic Sluge | |
| Quan et al. | Enhancing phosphorus removal by novel porous concrete fabricated with alkali-activated aggregate derived from industrial solid wastes | |
| KR101068008B1 (en) | The construction material utilizing sludge and its manufacturing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20120831 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20120831 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20140227 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20140318 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20140502 |
|
| 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: 20141125 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20141203 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5665071 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |