JP2020142192A - Sludge solidifying composition - Google Patents
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- JP2020142192A JP2020142192A JP2019040991A JP2019040991A JP2020142192A JP 2020142192 A JP2020142192 A JP 2020142192A JP 2019040991 A JP2019040991 A JP 2019040991A JP 2019040991 A JP2019040991 A JP 2019040991A JP 2020142192 A JP2020142192 A JP 2020142192A
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- 239000010802 sludge Substances 0.000 title claims abstract description 176
- 239000000203 mixture Substances 0.000 title claims abstract description 97
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims abstract description 41
- 239000000292 calcium oxide Substances 0.000 claims abstract description 31
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 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 abstract description 22
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 claims abstract description 18
- 229920000642 polymer Polymers 0.000 claims abstract description 18
- 229910000359 iron(II) sulfate Inorganic materials 0.000 claims abstract description 16
- 238000007711 solidification Methods 0.000 claims description 97
- 230000008023 solidification Effects 0.000 claims description 97
- 239000002956 ash Substances 0.000 claims description 20
- 239000004576 sand Substances 0.000 claims description 12
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 11
- 239000010883 coal ash Substances 0.000 claims description 11
- 239000000843 powder Substances 0.000 claims description 10
- 239000002893 slag Substances 0.000 claims description 10
- 150000008064 anhydrides Chemical class 0.000 claims description 9
- 229920006318 anionic polymer Polymers 0.000 claims description 7
- 229910001385 heavy metal Inorganic materials 0.000 abstract description 25
- 150000001450 anions Chemical class 0.000 abstract description 12
- 239000010865 sewage Substances 0.000 abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 37
- 235000012255 calcium oxide Nutrition 0.000 description 28
- 238000006703 hydration reaction Methods 0.000 description 23
- 229910001653 ettringite Inorganic materials 0.000 description 21
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 17
- 239000011398 Portland cement Substances 0.000 description 15
- 239000004568 cement Substances 0.000 description 15
- 238000000034 method Methods 0.000 description 14
- 239000010801 sewage sludge Substances 0.000 description 14
- 238000006243 chemical reaction Methods 0.000 description 13
- 230000036571 hydration Effects 0.000 description 11
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 10
- 239000003795 chemical substances by application Substances 0.000 description 10
- 239000013078 crystal Substances 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 239000011575 calcium Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 240000008042 Zea mays Species 0.000 description 6
- 235000005824 Zea mays ssp. parviglumis Nutrition 0.000 description 6
- 235000002017 Zea mays subsp mays Nutrition 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- -1 aluminum cations Chemical class 0.000 description 6
- 235000012241 calcium silicate Nutrition 0.000 description 6
- 229910052918 calcium silicate Inorganic materials 0.000 description 6
- 235000005822 corn Nutrition 0.000 description 6
- 150000004677 hydrates Chemical class 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 6
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 5
- 238000005266 casting Methods 0.000 description 5
- 238000002425 crystallisation Methods 0.000 description 5
- 230000008025 crystallization Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000010881 fly ash Substances 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- JHLNERQLKQQLRZ-UHFFFAOYSA-N calcium silicate Chemical compound [Ca+2].[Ca+2].[O-][Si]([O-])([O-])[O-] JHLNERQLKQQLRZ-UHFFFAOYSA-N 0.000 description 4
- 229910001430 chromium ion Inorganic materials 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000013329 compounding Methods 0.000 description 4
- 230000020169 heat generation Effects 0.000 description 4
- 150000004687 hexahydrates Chemical class 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 230000035515 penetration Effects 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000002689 soil Substances 0.000 description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 150000004645 aluminates Chemical class 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 229920006317 cationic polymer Polymers 0.000 description 3
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 244000144992 flock Species 0.000 description 3
- 230000003100 immobilizing effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 150000004682 monohydrates Chemical class 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- 238000006467 substitution reaction Methods 0.000 description 3
- 239000004135 Bone phosphate Substances 0.000 description 2
- 238000003991 Rietveld refinement Methods 0.000 description 2
- 235000010724 Wisteria floribunda Nutrition 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 2
- 159000000007 calcium salts Chemical class 0.000 description 2
- 239000000378 calcium silicate Substances 0.000 description 2
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 2
- ZHZFKLKREFECML-UHFFFAOYSA-L calcium;sulfate;hydrate Chemical compound O.[Ca+2].[O-]S([O-])(=O)=O ZHZFKLKREFECML-UHFFFAOYSA-L 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- BCAARMUWIRURQS-UHFFFAOYSA-N dicalcium;oxocalcium;silicate Chemical compound [Ca+2].[Ca+2].[Ca]=O.[O-][Si]([O-])([O-])[O-] BCAARMUWIRURQS-UHFFFAOYSA-N 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 238000005469 granulation Methods 0.000 description 2
- 230000003179 granulation Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 239000012784 inorganic fiber Substances 0.000 description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 description 2
- 229910000358 iron sulfate Inorganic materials 0.000 description 2
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 description 2
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 150000004692 metal hydroxides Chemical class 0.000 description 2
- 150000004686 pentahydrates Chemical class 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 150000004685 tetrahydrates Chemical class 0.000 description 2
- 238000009834 vaporization Methods 0.000 description 2
- 230000008016 vaporization Effects 0.000 description 2
- 238000004065 wastewater treatment Methods 0.000 description 2
- QJZYHAIUNVAGQP-UHFFFAOYSA-N 3-nitrobicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid Chemical compound C1C2C=CC1C(C(=O)O)C2(C(O)=O)[N+]([O-])=O QJZYHAIUNVAGQP-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 1
- VCUFZILGIRCDQQ-KRWDZBQOSA-N N-[[(5S)-2-oxo-3-(2-oxo-3H-1,3-benzoxazol-6-yl)-1,3-oxazolidin-5-yl]methyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C1O[C@H](CN1C1=CC2=C(NC(O2)=O)C=C1)CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F VCUFZILGIRCDQQ-KRWDZBQOSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- REDXJYDRNCIFBQ-UHFFFAOYSA-N aluminium(3+) Chemical compound [Al+3] REDXJYDRNCIFBQ-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- XFWJKVMFIVXPKK-UHFFFAOYSA-N calcium;oxido(oxo)alumane Chemical compound [Ca+2].[O-][Al]=O.[O-][Al]=O XFWJKVMFIVXPKK-UHFFFAOYSA-N 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- BFGKITSFLPAWGI-UHFFFAOYSA-N chromium(3+) Chemical compound [Cr+3] BFGKITSFLPAWGI-UHFFFAOYSA-N 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- JEGUKCSWCFPDGT-UHFFFAOYSA-N h2o hydrate Chemical compound O.O JEGUKCSWCFPDGT-UHFFFAOYSA-N 0.000 description 1
- 239000004021 humic acid Substances 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- SURQXAFEQWPFPV-UHFFFAOYSA-L iron(2+) sulfate heptahydrate Chemical compound O.O.O.O.O.O.O.[Fe+2].[O-]S([O-])(=O)=O SURQXAFEQWPFPV-UHFFFAOYSA-L 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 description 1
- 229910021653 sulphate ion Inorganic materials 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
Landscapes
- Treatment Of Sludge (AREA)
Abstract
Description
本発明は、下水等から発生する（都市）汚泥を短時間に固化せしめ、その汚泥固化体が水で再泥化することなく、固化強度の高い汚泥固化体となる汚泥固化用組成物に関する。 The present invention relates to a sludge solidification composition that solidifies (urban) sludge generated from sewage or the like in a short time, and the sludge solidified body becomes a sludge solidified body having high solidification strength without being re-mudged with water.
下水汚泥固化処理方法としては、下水汚泥焼却法あるいは下水汚泥溶融法が広く知られており、それらの焼却灰あるいは溶融灰（スラグ）を対象とした固化に関する技術も比較的多く知られている。 As a sewage sludge solidification treatment method, a sewage sludge incineration method or a sewage sludge melting method is widely known, and a relatively large number of techniques related to solidification of those incinerated ash or molten ash (slag) are also known.
一方、下水汚泥に対する濾過直後の水分の多いケーキを固化対象とする酸化カルシウム（ＣａＯ）を主成分とする複合系の固化剤、すなわち、複数成分からなる固化剤、及び固化処理技術が充分に検討されたとは言えず、寧ろ、このような水分の多いケーキを固化処理することにより、次工程での取り扱いや輸送、用途展開等が容易となる。 On the other hand, a complex solidifying agent containing calcium oxide (CaO) as a main component, which targets a cake having a large amount of water immediately after filtration for sewage sludge, that is, a solidifying agent composed of a plurality of components, and a solidifying treatment technique have been sufficiently studied. Rather, by solidifying such a cake with a large amount of water, it becomes easier to handle, transport, and develop applications in the next process.
従来より、下水等から発生する都市汚泥を水和・固化する汚泥固化材としては、酸化カルシウム（ＣａＯ）、或いは、これを主成分として含有するポルトランドセメントを主原料とするものが比較的広く知られている（特許文献１、２）。 Conventionally, as a sludge solidifying material that hydrates and solidifies urban sludge generated from sewage, etc., it is relatively widely known that calcium oxide (CaO) or Portland cement containing this as a main component is used as a main raw material. (Patent Documents 1 and 2).
酸化カルシウム（ＣａＯ）は、下水汚泥処理用固化剤として一般的に使用されており、酸化カルシウムの単品使用においては、水和による単位重量あたりの発熱量も大きく、発熱は瞬間的に起こる。さらに、酸化カルシウムの水和反応において、汚泥からの吸水と汚泥の固化が同時に起る。従って、汚泥との混合中から発熱と、温度上昇にともない水分の蒸発が可能である。 Calcium oxide (CaO) is generally used as a solidifying agent for treating sewage sludge, and when calcium oxide is used alone, the amount of heat generated per unit weight due to hydration is large, and heat generation occurs instantaneously. Furthermore, in the hydration reaction of calcium oxide, water absorption from sludge and solidification of sludge occur at the same time. Therefore, it is possible to generate heat during mixing with sludge and evaporate water as the temperature rises.
すなわち、酸化カルシウムを単独の組成で使用すると、水和反応による発熱、水分の気化と固化が進行する。その一方で、その混合物が、強アルカリ性のため、廃棄やリサイクル用としてはｐＨ調整などの配慮が必要となる。 That is, when calcium oxide is used alone, heat generation due to the hydration reaction and vaporization and solidification of water proceed. On the other hand, since the mixture is strongly alkaline, consideration such as pH adjustment is required for disposal and recycling.
また、酸化カルシウム単独系では、下水汚泥中の水分と反応してＣａ（ＯＨ）２を生成するが、反応する水分量は、下水汚泥処理用固化剤用途としては不充分であり、また、下水汚泥処理用固化剤用として、酸化カルシウムの単独使用では固化時間（強度が一定値になるまでの時間）の長いこと（例えば、１００ｋＮ／ｍ２程度のコーン指数に到達するのに３日間程度の養生を要する。）が問題となっていた。 Further, in the calcium oxide alone system, Ca (OH) 2 is produced by reacting with water in sewage sludge, but the amount of water that reacts is insufficient for use as a solidifying agent for sewage sludge treatment, and sewage. As a solidifying agent for sludge treatment, when calcium oxide is used alone, the solidification time (time until the strength reaches a constant value) is long (for example, it takes about 3 days to reach a cone index of about 100 kN / m 2 ). It requires curing.) Was a problem.
一方、酸化カルシウムを主成分とする水和・固化材料としては、ポルトランドセメント等のセメントがよく知られており、下水汚泥処理用固化剤としても使用されている（特許文献１、２）。 On the other hand, cement such as Portland cement is well known as a hydration / solidifying material containing calcium oxide as a main component, and is also used as a solidifying agent for sewage sludge treatment (Patent Documents 1 and 2).
酸化カルシウムは、セメントの主原料であり、セメントのグレードによって異なるが、通常、５５〜６５質量％程度含有されている。但し、セメント中の酸化カルシウムは、その大部分が、エーライト；Ｃ３Ｓ（３ＣａＯ・ＳｉＯ２），ビーライト；Ｃ２Ｓ（２ＣａＯ・ＳｉＯ２），アルミネート；Ｃ３Ａ（３ＣａＯ・Ａｌ２Ｏ３）等のカルシウム塩として存在しており、例えば、ポルトランドセメントでは、Ｃ３Ｓ＋Ｃ２Ｓの鉱物組成として７５〜８０質量％前後含有している。 Calcium oxide is the main raw material of cement and is usually contained in an amount of about 55 to 65% by mass, although it depends on the grade of cement. However, calcium oxide in the cement, most part, alite; C3S (3CaO · SiO 2) , belite; C2S (2CaO · SiO 2) , aluminate; C3A (3CaO · Al 2 O 3) such as It exists as a calcium salt. For example, Portland cement contains about 75 to 80% by mass of C3S + C2S as a mineral composition.
しかし、このように、セメント中では、酸化カルシウムがカルシウム塩の状態で存在しているため、水和反応の進行が上記の酸化カルシウム単独系に比較して著しく遅く（非特許文献１―３）、その結果、下水汚泥処理用固化剤に求められる程には、充分な発熱による温度上昇や水分の気化、蒸発は期待できない現状であった。また、下水汚泥等の都市汚泥に対するセメントの固化性は極めて不良であり、これについては、汚泥に含まれる微生物や有機物中のフミン酸の影響も大きいと考えられている。 However, since calcium oxide is present in the cement in the form of a calcium salt as described above, the progress of the hydration reaction is significantly slower than that of the above-mentioned calcium oxide alone system (Non-Patent Documents 1-3). As a result, it was not possible to expect a temperature rise, vaporization, or evaporation of water due to sufficient heat generation to the extent required for a solidifying agent for sewage sludge treatment. In addition, the solidification property of cement for urban sludge such as sewage sludge is extremely poor, and it is considered that the influence of humic acid in microorganisms and organic matter contained in the sludge is also large.
他方、かかるセメントにおける水和反応を詳細にみると、セメント水和生成物の中では、エトリンガイト（アルミン酸三硫酸カルシウム水和物：３ＣａＯ・Ａｌ２Ｏ３・３ＣａＳＯ４・３２Ｈ２Ｏ）が、最も多量の水を結晶水として保持し得ることが判った。この度、本発明者らは、この点に着目し、酸化カルシウムをベースとしつつも、迅速な水和反応により多量の水を結晶水として保持し得るエトリンガイトを主たる水和生成物とする汚泥固化用組成物を開発するべく、鋭意検討を重ねた結果、本発明を完成するに至った。 On the other hand, looking at the hydration reaction in such cements in detail, in the cement hydration products, ettringite (aluminate tribasic calcium sulfate hydrate: 3CaO · Al 2 O 3 · 3CaSO 4 · 32H 2 O) is, It was found that the largest amount of water could be retained as water of crystallization. Focusing on this point, the present inventors have focused on this point, and for sludge solidification using ettringite as a main hydration product, which is based on calcium oxide but can retain a large amount of water as water of crystallization by a rapid hydration reaction. As a result of diligent studies to develop the composition, the present invention has been completed.
しかしながら、従来のエトリンガイトを水和生成物とする汚泥固化用組成物は、上記したポルトランドセメント等のセメントを主原料とするものも含めて、おしなべて、反応完結が遅いという問題点を有していた。また、生成する汚泥固化体を路盤材等の有価物として再利用するためには、汚泥中に有害な重金属や陰イオンが混入する可能性があっても、これらの溶出を適切に防止することも望まれる。即ち、本発明の課題は、下水等から発生する汚泥を短時間に固化せしめ、汚泥中の水分の取り込み量（反応可能な水分量）を増大でき、生成する汚泥固化体が水で再泥化することなく、高強度であって、且つ、有害な重金属や陰イオンの固定が可能な汚泥固化体となる汚泥固化用組成物を提供することにある。 However, conventional sludge solidification compositions using ettringite as a hydration product, including those using cement as the main raw material such as the above-mentioned Portland cement, generally have a problem that the reaction completion is slow. .. In addition, in order to reuse the generated sludge solidified body as a valuable resource such as roadbed material, even if there is a possibility that harmful heavy metals and anions may be mixed in the sludge, it is necessary to appropriately prevent their elution. Is also desired. That is, the subject of the present invention is that sludge generated from sewage or the like can be solidified in a short time, the amount of water taken up in the sludge (reactive water amount) can be increased, and the produced sludge solidified body is remudged with water. It is an object of the present invention to provide a sludge solidifying composition which is a sludge solidified body which has high strength and can fix harmful heavy metals and anions.
すなわち、本発明は、以下の発明に関する。
［１］ 酸化カルシウム、硫酸アルミニウム、硫酸鉄（II）、及び、高分子凝集剤を含んでなる汚泥固化用組成物。
［２］ 前記汚泥固化用組成物１００質量部に対して、酸化カルシウムを３０〜８０質量部、硫酸アルミニウムを無水物換算で１０〜５０質量部、硫酸鉄（II）を無水物換算で５〜５０質量部、及び、高分子凝集剤を０．０１〜１．０質量部、含んでなる［１］に記載の汚泥固化用組成物。
［３］ 前記汚泥固化用組成物が、さらに、ペーパースラッジアッシュ、高炉スラグ、鋳物砂、および、石炭灰からなる群より選択された１種、或いは、２種以上を含んでなる［１］または［２］に記載の汚泥固化用組成物。
［４］ 前記汚泥固化用組成物１００質量部に対して、さらに、ペーパースラッジアッシュ、高炉スラグ、鋳物砂、および、石炭灰からなる群より選択された１種、或いは、２種以上を０．０１〜１０質量部、含んでなる［１］乃至［３］のいずれかに記載の汚泥固化用組成物。
［５］ 前記汚泥固化用組成物が、さらに、金属アルミニウム粉末を含んでなる［１］乃至［４］のいずれかに記載の汚泥固化用組成物。
［６］ 前記汚泥固化用組成物１００質量部に対して、さらに、金属アルミニウム粉末を０．０１〜５．０質量部、含んでなる［１］乃至［５］のいずれかに記載の汚泥固化用組成物。
［７］ 前記高分子凝集剤が、アニオン系高分子凝集剤である［１］乃至［６］のいずれかに記載の汚泥固化用組成物。
［８］ 排水処理で生じる汚泥を［１］乃至［７］のいずれかに記載の汚泥固化用組成物と接触させ、汚泥を固化することを特徴とする汚泥の固化方法。
That is, the present invention relates to the following invention.
[1] A composition for solidifying sludge, which comprises calcium oxide, aluminum sulfate, iron (II) sulfate, and a polymer flocculant.
[2] With respect to 100 parts by mass of the sludge solidification composition, 30 to 80 parts by mass of calcium oxide, 10 to 50 parts by mass of aluminum sulfate in terms of anhydride, and 5 to 50 parts by mass of iron (II) sulfate in terms of anhydride. The composition for solidifying sludge according to [1], which comprises 50 parts by mass and 0.01 to 1.0 parts by mass of a polymer flocculant.
[3] The sludge solidification composition further comprises one or more selected from the group consisting of paper sludge ash, blast furnace slag, foundry sand, and coal ash [1] or. The sludge solidification composition according to [2].
[4] With respect to 100 parts by mass of the sludge solidification composition, one kind or two or more kinds selected from the group consisting of paper sludge ash, blast furnace slag, cast sand, and coal ash were added to 0. The sludge solidification composition according to any one of [1] to [3], which comprises 01 to 10 parts by mass.
[5] The sludge solidification composition according to any one of [1] to [4], wherein the sludge solidification composition further contains a metallic aluminum powder.
[6] The sludge solidification according to any one of [1] to [5], which further comprises 0.01 to 5.0 parts by mass of metallic aluminum powder with respect to 100 parts by mass of the sludge solidification composition. Composition for.
[7] The sludge solidification composition according to any one of [1] to [6], wherein the polymer flocculant is an anionic polymer flocculant.
[8] A method for solidifying sludge, which comprises contacting sludge generated in wastewater treatment with the sludge solidification composition according to any one of [1] to [7] to solidify the sludge.
本発明によれば、下水等から発生する汚泥を短時間に固化せしめ、汚泥中の水分の取り込み量（反応可能な水分量）を増大できる結果、生成する汚泥固化体が水で再泥化することなく、高強度（例えば、３日程度の養生で、１５０ｋＮ／ｍ２以上のコーン指数に到達する。）の汚泥固化体を得ることができる汚泥固化用組成物を提供することができる。また、当該汚泥固化用組成物は、配合物質の粉体混合により簡便に製造できることから、かかる汚泥固化用組成物の製造方法を提供することができる。また、かかる汚泥固化用組成物の使用により、汚泥が含有する可能性のある重金属類や陰イオンを固定化させる効果も併せ持つ。さらに、かかる汚泥固化用組成物の使用により、従来のセメントや生石灰に比較して、大幅な固化時間短縮（例えば、７日程度の養生で、１５０〜３００ｋＮ／ｍ２程度のコーン指数に到達する。）を実現させ、次工程の作業性改善と固化処理土としての多様な再利用策を可能にさせ、経済的なメリットを与える。 According to the present invention, sludge generated from sewage or the like can be solidified in a short time, and the amount of water taken up in the sludge (reactive water amount) can be increased. As a result, the produced sludge solidified body is remudged with water. It is possible to provide a sludge solidifying composition capable of obtaining a sludge solidified body having high strength (for example, reaching a cone index of 150 kN / m 2 or more after curing for about 3 days) without any need. Further, since the sludge solidification composition can be easily produced by mixing powders of the compounding substances, it is possible to provide a method for producing such a sludge solidification composition. In addition, the use of the sludge solidification composition also has the effect of immobilizing heavy metals and anions that may be contained in the sludge. Furthermore, by using such a sludge solidification composition, the solidification time is significantly shortened as compared with conventional cement and quicklime (for example, after curing for about 7 days, a corn index of about 150 to 300 kN / m 2 is reached. ) Is realized, workability of the next process is improved, and various reuse measures as solidified treated soil are possible, giving economic merit.
本発明は、酸化カルシウムをベースとしつつも、迅速な水和反応により汚泥固化体内に多量の水を保持し得るとともに、汚泥中の有害な重金属や陰イオンの当該汚泥固化体からの溶出を効果的に防止でき、且つ、高強度の汚泥固化体を形成する汚泥固化用組成物を提供するものである。 Although the present invention is based on calcium oxide, a large amount of water can be retained in the sludge solidified body by a rapid hydration reaction, and harmful heavy metals and anions in the sludge are effectively eluted from the sludge solidified body. It is an object of the present invention to provide a sludge solidifying composition which can be prevented and forms a high-strength sludge solidified body.
以下、本発明を詳細に説明する。
本発明の汚泥固化用組成物は、酸化カルシウム、硫酸アルミニウム、硫酸鉄（II）、及び、高分子凝集剤を含んでなるものである。
Hereinafter, the present invention will be described in detail.
The sludge solidifying composition of the present invention comprises calcium oxide, aluminum sulfate, iron (II) sulfate, and a polymer flocculant.
酸化カルシウムは、本発明の汚泥固化用組成物中、固化(固結化)して高強度のエトリンガイトを形成する際の主要成分である。 Calcium oxide is a main component in the sludge solidification composition of the present invention when it is solidified (consolidated) to form high-strength ettringite.
硫酸アルミニウムは、本発明の汚泥固化用組成物中、固化反応系にアルミニウムカチオンと硫酸根を導入して上記酸化カルシウムと反応してエトリンガイトの生成を促す成分である。硫酸アルミニウムには、無水塩の他、６水塩（６水和物）、１０水塩（１０水和物）、１４水塩（１４水和物）、１５水塩（１５水和物）、１６水塩（１６水和物）、１８水塩（１８水和物）、及び、２７水塩（２７水和物）等の水和物が数多く知られており、本発明には、無水塩及びすべての水和物およびこれらの任意種類且つ任意割合の混合物が使用可能であるが、特に、無水塩及び６水塩（６水和物）、１０水塩（１０水和物）、１４水塩（１４水和物）、１５水塩（１５水和物）、１６水塩（１６水和物）が好適に使用可能である。 Aluminum sulfate is a component in the sludge solidification composition of the present invention that introduces aluminum cations and sulfate roots into the solidification reaction system and reacts with the above-mentioned calcium oxide to promote the formation of ettringite. In addition to anhydrous salts, aluminum sulfate includes hexahydrate (hexahydrate), 10-hydrate (10-hydrate), 14-hydrate (14-hydrate), 15-hydrate (15-hydrate), and the like. Many hydrates such as 16-hydrate (16-hydrate), 18-hydrate (18-hydrate), and 27-hydrate (27-hydrate) are known, and in the present invention, anhydrous salts are known. And all hydrates and any kind and any proportion of mixtures thereof can be used, but in particular anhydrous and hexahydrate (hexahydrate), 10-hydrate (10-hydrate), 14 water. A salt (14 hydrate), a 15 hydroxide (15 hydrate), and a 16 hydroxide (16 hydrate) can be preferably used.
硫酸鉄（II）は、上記硫酸アルミニウムと同様に硫酸根を補充してエトリンガイトの生成を促すことに加えて、例えば、六価クロムイオンのような有害な重金属イオンを毒性のないクロム（III）等のより低原子価の状態に還元する一方、自らは、酸化されて硫酸鉄（III）となり、生成したエトリンガイトのアルミニウムイオンの結晶格子中に取り込まれ、有害な重金属イオンを捕捉、不溶化する等の機能を有する成分である。硫酸鉄（II）には、無水塩の他、１水塩（１水和物）、４水塩（４水和物）、５水塩（５水和物）、及び、７水塩（７水和物）等の水和物が数多く知られており、本発明には、無水塩及びすべての水和物およびこれらの任意種類且つ任意割合の混合物が使用可能であるが、特に、無水塩、或いは、１水塩（１水和物）が好適に使用可能である。 Iron (II) sulfate, like aluminum sulfate, supplements sulfate roots and promotes the production of ettringite, and in addition, does not toxic chromium (III) harmful heavy metal ions such as hexavalent chromium ions. While reducing to a lower valence state such as, it is oxidized to iron (III) sulfate and incorporated into the crystal lattice of the aluminum ions of the ettringite produced, capturing harmful heavy metal ions and insolubilizing them. It is a component having the function of. Iron (II) sulfate includes anhydrous salts, monohydrates (monohydrates), tetrahydrates (tetrahydrates), pentahydrates (pentahydrates), and seven hydroxides (7). Many hydrates such as hydrates) are known, and anhydrous salts and all hydrates and mixtures of any kind and any ratio thereof can be used in the present invention, and in particular, anhydrous salts. Alternatively, monohydrate (monohydrate) can be preferably used.
高分子凝集剤は、塩基性条件下で生成した有害重金属水酸化物を固定化する一方、汚泥中の水分を吸収して汚泥固化体の固化強度の向上に寄与することに加えて、汚泥固化体の団粒化（粒状化）を促進し、後工程でのハンドリングや乾燥などを容易にする機能を有する。 The polymer flocculant immobilizes harmful heavy metal hydroxides produced under basic conditions, while absorbing moisture in sludge to contribute to improving the solidification strength of sludge solidified bodies, as well as sludge solidification. It has the function of promoting agglomeration (granulation) of the body and facilitating handling and drying in the subsequent process.
本発明の汚泥固化用組成物では、かかる汚泥固化用組成物１００質量部に対して、酸化カルシウムを３０〜８０質量部、硫酸アルミニウムを無水物換算で１０〜５０質量部、硫酸鉄（II）を無水物換算で５〜５０質量部、及び、高分子凝集剤を０．０１〜１．０質量部含んでなるように配合することが望ましい。迅速な水和・固化反応と汚泥固化体の固化強度の確保との両立を実現できるからである。 In the sludge solidification composition of the present invention, with respect to 100 parts by mass of the sludge solidification composition, 30 to 80 parts by mass of calcium oxide, 10 to 50 parts by mass of aluminum sulfate in terms of anhydride, iron (II) sulfate. It is desirable to mix 5 to 50 parts by mass in terms of anhydride and 0.01 to 1.0 part by mass of the polymer flocculant. This is because it is possible to achieve both a rapid hydration / solidification reaction and ensuring the solidification strength of the sludge solidified body.
さらに、本発明においては、酸化カルシウムに対する硫酸アルミニウム及び硫酸鉄（II）の割合が重要で、酸化カルシウム１質量部に対して硫酸アルミニウムを無水物換算で０．０７〜１.６０質量部程度配合するのが好ましく、０．０８〜１.４０質量部程度配合するのが更に好ましく、０.１０〜１.２０質量部程度配合するのが特に好ましい。また、酸化カルシウム１質量部に対して硫酸鉄（II）を無水物換算で０．０４〜１.６０質量部程度配合するのが好ましく、０．０５〜１.４０質量部程度配合するのが更に好ましく、０．０６〜１.２０質量部程度配合するのが特に好ましい。 Further, in the present invention, the ratio of aluminum sulfate and iron (II) sulfate to calcium oxide is important, and about 0.07 to 1.60 parts by mass of aluminum sulfate is mixed with 1 part by mass of calcium oxide in terms of anhydride. It is preferable to add about 0.08 to 1.40 parts by mass, and it is particularly preferable to add about 0.1 to 1.20 parts by mass. Further, it is preferable to add iron (II) sulfate to 1 part by mass of calcium oxide in an amount of about 0.04 to 1.60 parts by mass in terms of anhydride, and it is preferable to add about 0.05 to 1.40 parts by mass. It is more preferable, and it is particularly preferable to blend about 0.06 to 1.20 parts by mass.
一方、本発明における硫酸アルミニウムに対する硫酸鉄（II）の割合については、硫酸アルミニウム１質量部に対して硫酸鉄（II）を無水物換算で０．０８〜５.８０質量部程度配合するのが好ましく、０.１０〜５.００質量部程度配合するのが更に好ましく、０.１２〜３.００質量部程度配合するのが特に好ましい。 On the other hand, regarding the ratio of iron (II) sulfate to aluminum sulfate in the present invention, it is recommended to add iron (II) sulfate to 1 part by mass of aluminum sulfate in an amount of about 0.08 to 5.80 parts by mass in terms of anhydride. It is more preferable to blend about 0.1 to 5.00 parts by mass, and particularly preferably about 0.12 to 3.00 parts by mass.
本発明の汚泥固化用組成物では、かかる汚泥固化用組成物が、さらに、ペーパースラッジアッシュ（paper sludge ash）、高炉スラグ（blast furnace slag）、鋳物砂（foundry sand）、および、石炭灰からなる群より選択された１種、或いは、２種以上を含んでなる汚泥固化用組成物とすることができる。これらの固化助剤の添加により、これらの固化助剤が含有するシリカ（ＳiＯ２）による所謂、ポゾラン反応が促進され、更なる汚泥固化体の固化強度の向上が可能となるからである。 In the sludge solidification composition of the present invention, the sludge solidification composition further comprises paper sludge ash, blast furnace slag, foundry sand, and coal ash. It can be a sludge solidification composition containing one kind or two or more kinds selected from the group. This is because the addition of these solidifying aids promotes the so-called pozzolan reaction with silica (SiO 2 ) contained in these solidifying aids, and further improves the solidification strength of the sludge solidified body.
例えば、ペーパースラッジアッシュ（製紙スラッジ焼却灰、ＰＳ灰）は、製紙工場等から排出されるペーパースラッジを焼却したものであって、シリカ（ＳiＯ２）を約４０％、石灰（ＣａＯ）を約３０％、及びアルミナ（Ａｌ２Ｏ３）を約２５％程度含有するものが好ましい。本発明においては、上記ポゾラン反応による更なる汚泥固化体の固化強度の向上に加えて、ペーパースラッジアッシュ自体が、多孔質であるため、その孔表面に重金属等を吸着、固定する機能を有する。 For example, paper sludge ash (paper sludge incineration ash, PS ash) is obtained by incinerating paper sludge discharged from a paper manufacturing factory or the like, and contains about 40% silica (SiO 2 ) and about 30 lime (CaO). %, And those containing about 25% of alumina (Al 2 O 3 ) are preferable. In the present invention, in addition to further improving the solidification strength of the sludge solidified body by the pozzolan reaction, since the paper sludge ash itself is porous, it has a function of adsorbing and fixing heavy metals and the like on the pore surface.
高炉スラグは、石灰（ＣａＯ）とともにシリカ（ＳiＯ２）を主成分とし、その他の成分として、アルミナ（Ａｌ２Ｏ３）、酸化マグネシウム（ＭｇＯ）を含むものが使用可能であり、所謂、潜在水硬性及びポゾラン反応性を有するＳiＯ２含有物質として機能するものが好ましい。 As the blast furnace slag, those containing silica (SiO 2 ) as a main component together with lime (CaO) and alumina (Al 2 O 3 ) and magnesium oxide (MgO) as other components can be used, so-called latent water. Those that function as a SiO 2- containing substance having hardness and pozzolan reactivity are preferable.
鋳物砂は、鋳物の鋳造に用いられる鋳物砂型用途の砂であって、ケイ砂（ＳiＯ２）を主成分としており、これが、ポゾラン反応性を有するＳｉＯ２含有物質として機能するものが好ましい。 The casting sand is sand for casting sand molds used for casting castings, and is preferably composed of silica sand (SiO 2 ) as a main component, which functions as a SiO 2- containing substance having pozzolan reactivity.
石炭灰は、「クリンカアッシュ」と「フライアッシュ」等に大別される。「クリンカアッシュ」とは、石炭を炉内で燃焼させることによって生じた石炭灰の粒子が相互に凝集し、多孔質な塊となって炉底に落下堆積したものを、粉砕機で砕いたものである。「クリンカアッシュ」は、主成分として、シリカ（ＳiＯ２）を約６０％程度、アルミナ（Ａｌ２Ｏ３）を約２０〜２５％程度含有するものが好ましい。 Coal ash is roughly classified into "clinker ash" and "fly ash". "Clinker ash" is a crusher that crushes coal ash particles produced by burning coal in a furnace, which are aggregated together to form a porous mass that falls and accumulates on the bottom of the furnace. Is. The "clinker ash" preferably contains about 60% of silica (SiO 2 ) and about 20 to 25% of alumina (Al 2 O 3 ) as main components.
「クリンカアッシュ」としては、０．２〜２０μｍ程度の小さな空隙構造を有する多孔質体のものが例示される。これは、保水性に優れると共に、汚泥中の重金属等を効果的に吸着させることもできる。「フライアッシュ」としては、粉状に砕いた石炭をボイラ内で燃焼させた際、この燃焼により溶融状態になった灰の粒子が、高温の燃焼ガス中を浮遊した後、ボイラ出口で温度低下にともなって、冷却固化して球形微細粒子となったものが好ましい。 Examples of the "clinker ash" include a porous body having a small void structure of about 0.2 to 20 μm. This is excellent in water retention and can effectively adsorb heavy metals and the like in sludge. As "fly ash", when crushed coal is burned in a boiler, ash particles melted by this combustion float in high-temperature combustion gas, and then the temperature drops at the boiler outlet. Along with this, it is preferable that the particles are cooled and solidified into spherical fine particles.
「フライアッシュ」としては、主成分として、シリカ（ＳiＯ２）を約４０〜７５％、アルミナ（Ａｌ２Ｏ３）を約１５〜３５％含有するものが好ましい。「フライアッシュ」としては、比表面積２５００ｃｍ2／ｇ程度以上を有するものが例示され、保水性に優れていると共に、汚泥中の重金属等を効果的に吸着させることもできる。 The "fly ash" preferably contains about 40 to 75% of silica (SiO 2 ) and about 15 to 35% of alumina (Al 2 O 3 ) as main components. Examples of the "fly ash" include those having a specific surface area of about 2500 cm 2 / g or more, which are excellent in water retention and can effectively adsorb heavy metals and the like in sludge.
本発明においては、ポゾラン反応性を有するＳiＯ２含有物質であることから、「クリンカアッシュ」や「フライアッシュ」を含むあらゆる石炭灰が好適に使用される。 In the present invention, since it is a SiO 2- containing substance having pozzolan reactivity, any coal ash including "clinker ash" and "fly ash" is preferably used.
すなわち、本発明においては、本発明の汚泥固化用組成物１００質量部に対して、ペーパースラッジアッシュ、高炉スラグ、鋳物砂、および、石炭灰からなる群より選択された１種、或いは、２種以上の添加物を０．０１〜１０質量部、含んでなる汚泥固化用組成物とすることができる。すなわち、０．０１質量部未満の添加量では実質的な添加効果が認められず、１０質量部を超えて添加すると、上記ポゾラン反応の反応速度が遅くなるため、好ましくない。 That is, in the present invention, one or two types selected from the group consisting of paper sludge ash, blast furnace slag, cast sand, and coal ash with respect to 100 parts by mass of the sludge solidification composition of the present invention. A sludge solidification composition containing 0.01 to 10 parts by mass of the above additives can be obtained. That is, if the addition amount is less than 0.01 parts by mass, no substantial addition effect is observed, and if the addition amount exceeds 10 parts by mass, the reaction rate of the pozzolan reaction becomes slow, which is not preferable.
上記のペーパースラッジアッシュ、高炉スラグ、鋳物砂、および、石炭灰からなる群より選択された１種、或いは、２種以上の添加物の添加量としては、汚泥固化用組成物１００質量部に対して単独で、或いは、これらの２種以上の混合物として、２．０以上、８．０質量部以下程度が好ましく、汚泥固化用組成物１００質量部に対して３．０以上、７．０質量部以下程度が更に好ましく、汚泥固化用組成物１００質量部に対して４．０以上、６．０質量部以下程度が特に好ましい。 The amount of one or more additives selected from the group consisting of the above-mentioned paper sludge ash, blast furnace slag, cast sand, and coal ash is 100 parts by mass of the sludge solidification composition. It is preferably 2.0 or more and 8.0 parts by mass or less, and 3.0 or more and 7.0 parts by mass with respect to 100 parts by mass of the sludge solidification composition, alone or as a mixture of these two or more kinds. It is more preferably about 40 parts by mass or less, and particularly preferably about 4.0 parts by mass or more and 6.0 parts by mass or less with respect to 100 parts by mass of the sludge solidification composition.
本発明の汚泥固化用組成物は、さらに、金属アルミニウム粉末を含んでなる汚泥固化用組成物とすることができる。金属アルミニウムは、水、或いは、水と酸化カルシウム（ＣａＯ）の反応生成物である水酸化カルシウム（Ｃａ（ＯＨ）２）と反応し、その反応熱で水和・固化反応全体を迅速に促進させることができ、該反応後は、アルミニウム（III）となって、汚泥固化体中に取り込まれる。 The sludge solidification composition of the present invention can be further made into a sludge solidification composition containing a metallic aluminum powder. Metallic aluminum reacts with water or calcium hydroxide (Ca (OH) 2 ), which is a reaction product of water and calcium oxide (CaO), and the heat of the reaction rapidly accelerates the entire hydration / solidification reaction. After the reaction, it becomes aluminum (III) and is incorporated into the sludge solidified body.
この場合、本発明の汚泥固化用組成物１００質量部に対して、さらに、金属アルミニウム粉末を０．０１〜５．０質量部、含んでなる汚泥固化用組成物とすることができる。すなわち、０．０１質量部以下の添加量では実質的な添加効果が充分ではなく、５．０質量部以上添加すると、短時間での過剰な発熱により、水和・固化反応全体の制御が困難となることがある。金属アルミニウム粉末は、水、或いは、水酸化カルシウムと円滑に反応し得る充分な比表面積を確保できる１ｍｍφ以下のものが好適に使用される。 In this case, the sludge solidification composition containing 0.01 to 5.0 parts by mass of metallic aluminum powder with respect to 100 parts by mass of the sludge solidification composition of the present invention can be obtained. That is, if the addition amount is 0.01 parts by mass or less, the substantial addition effect is not sufficient, and if 5.0 parts by mass or more is added, it is difficult to control the entire hydration / solidification reaction due to excessive heat generation in a short time. May become. As the metallic aluminum powder, one having a diameter of 1 mm or less that can secure a sufficient specific surface area capable of smoothly reacting with water or calcium hydroxide is preferably used.
かかる金属アルミニウム粉末の添加量としては、汚泥固化用組成物１００質量部に対して１．０以上、４．０質量部以下程度が好ましく、汚泥固化用組成物１００質量部に対して１．５以上、３．５質量部以下程度が更に好ましく、汚泥固化用組成物１００質量部に対して２．０以上、３．０質量部以下程度が特に好ましい。 The amount of the metallic aluminum powder added is preferably 1.0 or more and 4.0 parts by mass or less with respect to 100 parts by mass of the sludge solidification composition, and 1.5 by mass with respect to 100 parts by mass of the sludge solidification composition. As mentioned above, about 3.5 parts by mass or less is more preferable, and about 2.0 or more and 3.0 parts by mass or less is particularly preferable with respect to 100 parts by mass of the sludge solidification composition.
また、前記高分子凝集剤としては、粒子径１ｍｍφ以下の粉末状のものであれば、アニオン系高分子凝集剤、カチオン系高分子凝集剤、ノニオン系高分子凝集剤、或いは、これらの任意割合での混合物のいずれをも使用することができるが、本発明における高分子凝集剤としては、特に、アニオン系高分子凝集剤を好適に使用することができる。かかる高分子凝集剤は、塩基性条件下で生成した有害重金属水酸化物を固定化する一方、汚泥中の水分を吸収して汚泥固化体の固化強度の向上に寄与することに加えて、汚泥固化体の団粒化（粒状化）を促進し、後工程でのハンドリングや乾燥などを容易にする役割を担っている。 Further, the polymer flocculant is an anionic polymer flocculant, a cationic polymer flocculant, a nonionic polymer flocculant, or an arbitrary ratio thereof as long as it is a powder having a particle diameter of 1 mmφ or less. Any of the mixtures in the above can be used, but as the polymer flocculant in the present invention, an anionic polymer flocculant can be preferably used. Such a polymer flocculant immobilizes harmful heavy metal hydroxides produced under basic conditions, and at the same time, absorbs water in sludge and contributes to improvement of solidification strength of sludge solidified body, and in addition, sludge. It promotes agglomeration (granulation) of the solidified material, and plays a role of facilitating handling and drying in the subsequent process.
アニオン系高分子凝集剤としては、ハイモ（株）製、ポリアクリルアミド系のハイモフロックＳＳ１３０、ＭＴアクアポリマー（株）製アコフロックＡ−１１０等が例示できるが、これらのみに限定されるものでないことは言うまでもない。本発明の汚泥固化用組成物におけるアニオン系高分子凝集剤の添加量としては、汚泥固化用組成物１００質量部に対して０．０１以上、１．０質量部以下程度が好ましく、汚泥固化用組成物１００質量部に対して０．２以上、０．８質量部以下程度が更に好ましく、汚泥固化用組成物１００質量部に対して０．４以上、０．６質量部以下程度が特に好ましい。 Examples of the anionic polymer flocculant include Hymo Flock SS130 manufactured by Hymo Co., Ltd., Polyacrylamide-based Hymovloc SS130, and Akovlock A-110 manufactured by MT Aquapolymer Co., Ltd., but the anionic polymer flocculant is not limited to these. Needless to say. The amount of the anionic polymer flocculant added to the sludge solidification composition of the present invention is preferably 0.01 or more and 1.0 part by mass or less with respect to 100 parts by mass of the sludge solidification composition, and is used for sludge solidification. It is more preferably 0.2 or more and 0.8 parts by mass or less with respect to 100 parts by mass of the composition, and particularly preferably 0.4 or more and 0.6 parts by mass or less with respect to 100 parts by mass of the sludge solidification composition. ..
カチオン系高分子凝集剤としては、ハイモ（株）製、ポリアクリルエステル系のハイモフロックＭＰ１８４、ＭＴアクアポリマー（株）製アロンフロックＣ−５０８等が例示できるが、これらのみに限定されるものでないことは言うまでもない。本発明の汚泥固化用組成物におけるカチオン系高分子凝集剤の添加量としては、汚泥固化用組成物１００質量部に対して０．０１以上、１．０質量部以下程度が好ましく、汚泥固化用組成物１００質量部に対して０．２以上、０．８質量部以下程度が更に好ましく、汚泥固化用組成物１００質量部に対して０．４以上、０．６質量部以下程度が特に好ましい。 Examples of the cationic polymer flocculant include, but are not limited to, Hymo Flock MP184 manufactured by Hymo Co., Ltd., Polyacrylic ester-based Hymovlock MP184, and Aron Flock C-508 manufactured by MT Aqua Polymer Co., Ltd. Needless to say. The amount of the cationic polymer flocculant added to the sludge solidification composition of the present invention is preferably 0.01 or more and 1.0 part by mass or less with respect to 100 parts by mass of the sludge solidification composition, and is used for sludge solidification. It is more preferably about 0.2 or more and 0.8 parts by mass or less with respect to 100 parts by mass of the composition, and particularly preferably about 0.4 or more and about 0.6 parts by mass or less with respect to 100 parts by mass of the sludge solidification composition. ..
ノニオン系高分子凝集剤としては、ハイモ（株）製、ポリアクリルアミド系のハイモフロックＡＰ１０５、ＭＴアクアポリマー（株）製アコフロックＮ−１０２等が例示できるが、これらのみに限定されるものでないことは言うまでもない。汚泥固化用組成物１００質量部に対して０．０１以上、１．０質量部以下程度が好ましく、汚泥固化用組成物１００質量部に対して０．２以上、０．８質量部以下程度が更に好ましく、汚泥固化用組成物１００質量部に対して０．４以上、０．６質量部以下程度が特に好ましい。 Examples of the nonionic polymer flocculant include, but are not limited to, Hymo Flock AP105 manufactured by Hymo Co., Ltd., Akovlock N-102 manufactured by MT Aqua Polymer Co., Ltd., and the like. Needless to say. It is preferably 0.01 or more and 1.0 part by mass or less with respect to 100 parts by mass of the sludge solidification composition, and 0.2 or more and 0.8 parts by mass or less with respect to 100 parts by mass of the sludge solidification composition. More preferably, it is 0.4 or more and 0.6 parts by mass or less with respect to 100 parts by mass of the sludge solidification composition.
本発明の汚泥固化用組成物における固化機構については、例えば、以下のように考えることができる。すなわち、酸化カルシウム（ＣａＯ）とＨ２Ｏが反応して、生成したＣａ（ＯＨ）２の溶解度分に相当するＣａイオンが溶出し、硫酸アルミニウムから生成した水酸化アルミニウムとの反応によりカルシウム−アルミネート（Calcium-Aluminate）化合物（３ＣａＯ・Ａｌ２Ｏ３・６Ｈ２Ｏなど）が生成し、さらに硫酸塩との反応によりカルシウム−アルミネート−サルフェート（Calcium-Aluminate-Sulfate）化合物のエトリンガイト（ettringite）［３ＣａＯ・Ａｌ２Ｏ３・３ＣａＳＯ４・３２Ｈ２Ｏ］（示性式では｛Ｃａ６［Ａｌ（ＯＨ）６］２・２４Ｈ２Ｏ｝（ＳＯ４）３・２Ｈ２Ｏと表される。）の無機繊維状多孔体を生成するに至るのではないかというものである。 The solidification mechanism in the sludge solidification composition of the present invention can be considered, for example, as follows. That is, by reacting with calcium oxide (CaO) H 2 O is, Ca ions corresponding to the generated Ca (OH) 2 solubility fraction is eluted, calcium by reaction with aluminum hydroxide produced from aluminum sulphate - Aluminum sulfonate (calcium-aluminate) compound (3CaO · Al 2 O 3 · 6H 2 O , etc.) is produced, further calcium by reaction with sulphate - aluminate - sulfate (calcium-aluminate-sulfate) compound ettringite (ettringite) [3CaO · Al 2 O 3 · 3CaSO 4 · 32H 2 O] ( in rational formula represented as {Ca 6 [Al (OH) 6] 2 · 24H 2 O} (SO 4) 3 · 2H 2 O. ) Is likely to produce an inorganic fibrous porous body.
エトリンガイトは、前述の技術文献１−３にも記載されるように、上述の特許文献１、２に例示されるような、ポルトランドセメントを主原料とする汚泥固化用組成物においても主要な水和生成物の一つである。しかしながら、上記したように、ポルトランドセメントの固化速度は汚泥固化用途の使用において充分速いというには程遠い現状である。 As described in the above-mentioned Technical Documents 1-3, ettringite is also a major hydration in a sludge solidification composition using Portland cement as a main raw material, as exemplified in the above-mentioned Patent Documents 1 and 2. It is one of the products. However, as described above, the solidification rate of Portland cement is far from sufficient for use in sludge solidification applications.
例えば、前述の技術文献１によると、ポルトランドセメントにおけるエーライト（Ｃ３Ｓ）の水和反応率が、８０％に到達するために要する時間は、７日前後であり、さらに、９０％に到達するために要する時間は、２８日以上である。一方、ビーライト（Ｃ２Ｓ）の水和反応率が、８０％に到達するために要する時間は、２８日以上である。従って、この事実からポルトランドセメント水和反応は、養生２８日においても、未だ完全固化に至っていないことが判る。 For example, according to the above-mentioned Technical Document 1, it takes about 7 days for the hydration reaction rate of A. Wright (C3S) in Portland cement to reach 80%, and further reaches 90%. The time required for this is 28 days or more. On the other hand, the time required for the hydration reaction rate of belite (C2S) to reach 80% is 28 days or more. Therefore, from this fact, it can be seen that the Portland cement hydration reaction has not yet reached complete solidification even after 28 days of curing.
また、技術文献２によると、ポルトランドセメント原料中のエーライトとビーライトにおけるモル比（Ｃ／Ｓ）はそれぞれ３及び２であるが、水和反応後、最終的には、いずれもＣ／Ｓ＝１．５に到達することになり、Ｃ／Ｓ＝１．５に到達した場合の化学式はＣ３Ｓ２Ｈ４として表記される。 Further, according to Technical Document 2, the molar ratios (C / S) of a.Wright and belite in the Portland cement raw material are 3 and 2, respectively, but after the hydration reaction, both are finally C / S. = 1.5 is reached, and the chemical formula when C / S = 1.5 is reached is expressed as C 3 S 2 H 4 .
一方、技術文献３では、ポルトランドセメントのカルシウムシリケート相中のエーライトの固化につき、材齢２８日のＣ／ＳのＴＥＭ−ＥＤＸによる直接測定値を１．８３、Ｘ線回折とＤＴＡ−ＴＧの測定結果から求めた計算値を１．７３と算定しており、いずれもＣ／Ｓ＝１．５には、未だ、到達しておらず、ポルトランドセメント水和反応は、養生２８日においても、未だ完全固化に至っていないことが示されている。 On the other hand, in Technical Document 3, regarding the solidification of alite in the calcium silicate phase of Portland cement, the direct measurement value of C / S of 28 days old by TEM-EDX was 1.83, and the X-ray diffraction and DTA-TG were used. The calculated value obtained from the measurement results was calculated to be 1.73, and none of them reached C / S = 1.5 yet, and the Portland cement hydration reaction continued even on the 28th day of curing. It has been shown that it has not yet been completely solidified.
さらに、技術文献１では、ポルトランドセメント中のエーライトとビーライトを含むカルシウムシリケート相の固化につき、材齢２８日のＣ／Ｓ比をＸ線回折／リートベルト法により、１．８３と算出しており、同様な結論が導かれる。 Further, in Technical Document 1, the C / S ratio at 28 days of age was calculated to be 1.83 by the X-ray diffraction / Rietveld method for the solidification of the calcium silicate phase containing a.Wright and belite in Portland cement. And a similar conclusion is drawn.
これに対して、本発明の汚泥固化用組成物は、汚泥に添加混合して固化処理することにより、汚泥を短時間（例えば、３日程度の養生で、１５０ｋＮ／ｍ２以上のコーン指数に到達する。）に固化せしめ、生成する汚泥固化体が水で再泥化することなく、高強度の汚泥固化体となるという本発明の顕著な効果を得ることができるが、これは、本発明によれば、酸化カルシウム由来のカルシウム成分と、硫酸アルミニウム中のアルミニウム成分が迅速に反応して、針状構造のエトリンガイトを速やかに形成して、多量の結晶水をその構造中に取り込む作用を有することから汚泥の含水量を早期に低下させるためではないかと考えられる。実際、エトリンガイトは、１分子あたり、３２分子の水を水和できる。 On the other hand, in the sludge solidification composition of the present invention, sludge is added and mixed with sludge and solidified to obtain a corn index of 150 kN / m 2 or more in a short time (for example, curing for about 3 days). It is possible to obtain the remarkable effect of the present invention that the sludge solidified body produced by solidifying the sludge solidified body becomes a high-strength sludge solidified body without being re-mudified with water. According to the report, the calcium component derived from calcium oxide reacts rapidly with the aluminum component in aluminum sulfate to rapidly form ettringite having a needle-like structure, and has an action of incorporating a large amount of crystalline water into the structure. Therefore, it is considered that this is to reduce the water content of sludge at an early stage. In fact, ettringite can hydrate 32 molecules of water per molecule.
さらに、上記したように、生成したエトリンガイトの結晶は、針状結晶が凝集した無機繊維多孔体であることから、固化処理した汚泥の構造補強材として機能し、汚泥固化体の固化強度の向上に寄与しているとも考えられる。 Further, as described above, since the produced ettringite crystals are inorganic fiber porous bodies in which acicular crystals are aggregated, they function as a structural reinforcing material for the solidified sludge and improve the solidification strength of the sludge solidified body. It is also considered to be contributing.
また、諸外国の都市汚泥等においては、工業排水等の混入により、有害な重金属類や陰イオンによる汚染の可能性も否定できない。これに対しては、生成する汚泥固化体を路盤材等の有価物として再利用する場合には充分な溶出防止の対策が必要となる。この点、エトリンガイト（［３ＣａＯ・Ａｌ２Ｏ３・３ＣａＳＯ４・３２Ｈ２Ｏ］：アルミン酸三硫酸カルシウム水和物）を主たる汚泥固化体の成分とする本発明の汚泥固化用組成物は、それ自体で汚泥中の有害な重金属等を固定化する機能をも有している。すなわち、重金属としてはＰｂ、Ｃｅ、Ｃｄ、Ｈｇ、Ａｓ等について、本発明の汚泥固化用組成物を使用すると、固定化が出来るとともに、陰イオンのＦ−、ＢＯ４ ３−、ＣＮ−、ＡｓＯ４ ３−、ＣｒＯ４ ２−、ＰＯ４ ３−等についても固定化可能である。 In addition, in urban sludge from other countries, the possibility of pollution by harmful heavy metals and anions due to contamination with industrial wastewater cannot be denied. On the other hand, when the generated sludge solidified body is reused as a valuable resource such as a roadbed material, sufficient measures to prevent elution are required. In this regard, ettringite: sludge solidified composition of the present invention that the ([3CaO · Al 2 O 3 · 3CaSO 4 · 32H 2 O] aluminate tribasic calcium sulfate hydrate) with the components of the primary sludge solid material, it It also has the function of immobilizing harmful heavy metals in sludge by itself. That is, as the heavy metal Pb, Ce, Cd, Hg, for As such, the use of sludge solidified composition of the present invention, it is immobilized, the anion F -, BO 4 3-, CN -, AsO 4 3-, CrO 4 2-, can also be immobilized for PO 4 3-, and the like.
これはエトリンガイトの構造内に、これらの重金属類や陰イオンが取込まれる事によるものである。すなわち、エトリンガイトは｛Ｃａ６［Ａｌ（ＯＨ）６・２４Ｈ２Ｏ］｝６＋の針状構造がＣ軸方向に伸びた骨格を形成しており、この間にＳＯ４四面体と水分子が入り込んだ結晶構造を有する。この結晶化の際にＡｌ原子の位置にイオン半径の近い重金属原子と容易に置換することが知られている。 This is due to the incorporation of these heavy metals and anions into the structure of ettringite. That is, ettringite forms a skeleton acicular structure 6+ {Ca 6 [Al (OH ) 6 · 24H 2 O]} is extended in the C-axis direction, enters the SO 4 tetrahedra with water molecules in the meantime It has a crystal structure. It is known that during this crystallization, the position of the Al atom is easily replaced with a heavy metal atom having an ionic radius close to that of the Al atom.
また、柱状構造間に介在する硫酸イオンも上記の陰イオンと置換することも可能である。これは、本発明の汚泥固化用組成物の使用により、エトリンガイトが生成する際のカルシウム−アルミネート−サルフェート（Calcium-Aluminate-Sulfate）の水和結晶化の際に、置換反応が起り、これにより、結晶構造内に重金属や陰イオンを固定化するものである。例えば、六価クロムイオン（Ｃｒ６＋）は、クロム酸イオンとして、硫酸イオンと置換固溶してクロムエトリンガイト（［３ＣａＯ・Ａｌ２Ｏ３・３ＣａＣｒＯ４・３２Ｈ２Ｏ］）となり、エトリンガイト結晶中に固定されるというものである。さらに、ｐＨ：１０以上において、かかるエトリンガイト構造は極めて安定であることから、その結果、固定化された重金属や陰イオンは長期間安定に固定化されて存在する特徴があると言える。 It is also possible to replace the sulfate ion intervening between the columnar structures with the above-mentioned anion. This is because the use of the sludge solidification composition of the present invention causes a substitution reaction during the hydration crystallization of Calcium-Aluminate-Sulfate during the formation of ettringite, which causes a substitution reaction. , It immobilizes heavy metals and anions in the crystal structure. For example, hexavalent chromium ions (Cr 6+), as a chromic acid ion, chromium et Trinh Gaito replaced solid solution with sulfate ion ([3CaO · Al 2 O 3 · 3CaCrO 4 · 32H 2 O]) , and the in ettringite crystals It is to be fixed. Furthermore, since the ettringite structure is extremely stable at pH: 10 or higher, it can be said that the immobilized heavy metals and anions are characterized by being stably immobilized for a long period of time.
加えて、生成したエトリンガイトの結晶は、針状結晶が凝集した無機繊維多孔体であることから、その比表面積は極めて大きく、上記の化学的な置換固溶に加えて、重金属イオン等の表面吸着による固定も重金属類等の固定に寄与しているものと考えられる。 In addition, since the produced ettringite crystal is an inorganic fiber porous body in which acicular crystals are aggregated, its specific surface area is extremely large, and in addition to the above-mentioned chemical substitution solid solution, surface adsorption of heavy metal ions and the like is performed. It is considered that the fixing by is also contributing to the fixing of heavy metals and the like.
一方、本発明の汚泥固化用組成物は、上記のとおり、硫酸鉄（II）を含有し、例えば、六価クロムイオンのような有害な重金属イオンを，毒性のない三価のクロムイオンの状態に還元する一方、自らは、酸化されて硫酸鉄（III）となり、生成したエトリンガイトのアルミニウムイオンの結晶格子中に取り込まれると考えられる（Goeril Moechner et.al, Cement and Concrete Research 39 (2009) 482-489参照）。 On the other hand, the sludge solidification composition of the present invention contains iron (II) sulfate as described above, and is in the state of non-toxic trivalent chromium ions, for example, harmful heavy metal ions such as hexavalent chromium ions. On the other hand, it is thought that it is oxidized to iron (III) sulfate and incorporated into the crystal lattice of the aluminum ions of the produced ettringite (Goeril Moechner et.al, Cement and Concrete Research 39 (2009) 482). See -489).
同時に、本発明は、排水処理で生じる汚泥に上記の汚泥固化用組成物を添加混合して固化することを特徴とする汚泥の固化方法をも開示するものである。これにより、下水等から発生する汚泥を短時間（例えば、３日程度の養生で、１５０ｋＮ／ｍ２以上のコーン指数に到達する。）に固化せしめ、汚泥中の水分の取り込み量（反応可能な水分量）を増大できる結果、生成する汚泥固化体が水で再泥化することなく、高強度の汚泥固化体とすることができる。また、この汚泥の固化方法により、含有する重金属類や陰イオンを固定化させる効果も併せ持つ。さらに、従来のセメントや生石灰より大幅に固化時間を短縮させ、次工程の作業性改善と固化処理土の多様な再利用策を可能にさせ、経済的なメリットを与えることができる。 At the same time, the present invention also discloses a sludge solidification method, which comprises adding and mixing the above sludge solidification composition to sludge generated in wastewater treatment and solidifying the sludge. As a result, sludge generated from sewage or the like is solidified in a short time (for example, it reaches a corn index of 150 kN / m 2 or more after curing for about 3 days), and the amount of water taken up in the sludge (reactable). As a result of being able to increase the amount of water), the sludge solidified body produced can be made into a high-strength sludge solidified body without being re-mudged with water. In addition, this sludge solidification method also has the effect of immobilizing heavy metals and anions contained therein. Furthermore, the solidification time can be significantly shortened compared to conventional cement and quicklime, workability of the next process can be improved, and various measures for reusing the solidified treated soil can be made, which can provide economic benefits.
具体的には、本発明の汚泥固化方法における汚泥への本発明の汚泥固化用組成物の添加量は、対象汚泥の含水率や、要求される汚泥固化体の固化強度にも拠るが、下記のようにすることが好ましい。すなわち、対象汚泥に本発明の汚泥固化用組成物を万遍なく添加混合して固化して、例えば、温度：２０℃、湿度：１００％（２０℃）の条件下で、７日間密閉養生したときのコーン指数が、１５０ｋＮ／ｍ２以上、好ましくは２００ｋＮ／ｍ２以上、より好ましくは２５０ｋＮ／ｍ２以上となるように、その添加量を調整することで、より安定した処理が行えるようになる。 Specifically, the amount of the sludge solidification composition of the present invention added to the sludge in the sludge solidification method of the present invention depends on the water content of the target sludge and the required solidification strength of the sludge solidified body, but is as follows. It is preferable to do so. That is, the sludge solidification composition of the present invention was evenly added to and mixed with the target sludge to solidify it, and the sludge was hermetically cured for 7 days under the conditions of, for example, temperature: 20 ° C. and humidity: 100% (20 ° C.). By adjusting the addition amount so that the cone index at that time is 150 kN / m 2 or more, preferably 200 kN / m 2 or more, more preferably 250 kN / m 2 or more, more stable processing can be performed. Become.
上記のコーン指数の測定は、「締固めた土のコーン指数試験方法 ＪＩＳ Ａ１２２８」に準拠して以下のように行なった。 The above-mentioned measurement of the corn index was carried out as follows in accordance with "Compacted soil corn index test method JIS A1228".
すなわち、４．７５ｍｍのふるいを通過させた試料を内径１０ｃｍの突固め試験用モールドに３層に分けて投入し、２．５ｋｇのランマーで落下高さ３０ｃｍ、各層２５回ずつ、突固めて供試体を作製した。 That is, the sample passed through the 4.75 mm sieve is put into a compaction test mold having an inner diameter of 10 cm in three layers, and the sample is compacted with a 2.5 kg rammer at a drop height of 30 cm and 25 times for each layer. A specimen was prepared.
次に、供試体上端面中央部にコーンペネトロメーターを鉛直に立て、これを１ｃｍ／ｓの速さで貫入させ、コーン先端の貫入量が、供試体上端面から、５ｃｍ、７．５ｃｍおよび１０ｃｍのときの平均貫入抵抗力を求める。コーン指数ｑｃ（ｋＮ／ｍ２）は、上記３点の貫入抵抗力の平均値Ｑｃ（Ｎ）をコーン先端の底面積Ａ（３．２４ｃｍ２）で除してコーン指数を求めた。
Ｑｃ：平均貫入抵抗力（Ｎ）
Ａ ：コーン先端の底面積（ｃｍ２）
Next, a cone penetrometer was erected vertically in the center of the upper end surface of the specimen and penetrated at a speed of 1 cm / s, and the penetration amount of the cone tip was 5 cm, 7.5 cm and 5 cm from the upper end surface of the specimen. Find the average penetration resistance at 10 cm. The cone index q c (kN / m 2 ) was obtained by dividing the average value Q c (N) of the penetration resistance at the above three points by the bottom area A (3.24 cm 2 ) at the tip of the cone.
Q c : Average penetration resistance (N)
A: Bottom area of cone tip (cm 2 )
次に、実施例により、本発明を具体的に説明する。 Next, the present invention will be specifically described with reference to Examples.
［試料の調製］
国内で発生した某下水汚泥（生汚泥）を「下水汚泥サンプル」として使用した。該「下水汚泥サンプル」は、１１０℃乾燥における含水比が、４８７％、ｐＨ（２５℃）が５．３２、湿潤密度が０．９９４ｇ／ｍｌであった。
[Sample preparation]
A certain sewage sludge (raw sludge) generated in Japan was used as a "sewage sludge sample". The "sewage sludge sample" had a water content ratio of 487%, a pH (25 ° C.) of 5.32, and a wet density of 0.994 g / ml when dried at 110 ° C.
上記「下水汚泥サンプル」１０Ｌ（リットル）に対して、下記の表１の配合組成（実施例１―１８及び比較例１―３）を有する各汚泥固化用組成物１ｋｇを添加混合した後、温度：２０℃、２０℃の空気中で、密閉養生して得られた汚泥固化体につき、養生３日後と７日間後にコーン指数を測定した。 To 10 L (liter) of the above "sewage sludge sample", 1 kg of each sludge solidifying composition having the compounding composition (Examples 1-18 and Comparative Example 1-3) shown in Table 1 below is added and mixed, and then the temperature is adjusted. : The corn index of the sludge solidified body obtained by closed curing in air at 20 ° C. and 20 ° C. was measured 3 days and 7 days after curing.
使用した各組成物の原材料を以下に示す。
すなわち、酸化カルシウム（ＣａＯ）は、富士フィルム和光純薬（株）製の試薬を使用した。硫酸アルミニウム・１５水和物（ＡＳ・１５Ｈ２Ｏ）は、大明化学工業（株）製のものを使用し、硫酸アルミニウム・無水物は、大明化学工業（株）製の対応する１５水和物を５００℃で、２時間焼成して調製した。また、硫酸鉄（II）・１水和物（ＦｅＳＯ４・Ｈ２Ｏ）及び硫酸鉄（II）・７水和物（ＦｅＳＯ４・７Ｈ２Ｏ）は、富士フィルム和光純薬（株）製の試薬を使用した。一方、ポルトランドセメントは、太平洋セメント（株）製のものを使用した。さらに、高分子凝集剤は、ＭＴアクアポリマー（株）製、Ａ−１１０（アニオン性）を使用した。鋳物砂は、旭有機材（株）製のものを使用し、高炉スラグは、ＪＦＥミネラル（株）製のもの、石炭灰は、中国電力（株）製フライアッシュII種を使用した。また、ペーパースラッジアッシュは、（株）ＥＴＳジャパン製エコソイルＰを使用した。さらに、金属アルミニウム粉末は、山石金属（株）製のものを使用した。
コーン指数は、ＪＩＳ Ａ１２２８に準じて上記のように測定した。
The raw materials for each composition used are shown below.
That is, as calcium oxide (CaO), a reagent manufactured by Fuji Film Wako Pure Chemical Industries, Ltd. was used. Aluminum sulfate 15 hydrate (AS-15H 2 O), use those made by Taimei Chemicals Co., aluminum sulfate anhydride, the corresponding 15-hydrate manufactured by Taimei Chemicals Co. Was calcined at 500 ° C. for 2 hours to prepare. Moreover, iron sulfate (II) · 1 hydrate (FeSO 4 · H 2 O) and iron sulfate (II) · 7 hydrate (FeSO 4 · 7H 2 O) is produced by Fuji Film manufactured by Wako Pure Chemical Industries, Reagent was used. On the other hand, Portland cement used was made by Taiheiyo Cement Co., Ltd. Further, as the polymer flocculant, A-110 (anionic) manufactured by MT Aquapolymer Co., Ltd. was used. The casting sand used was made by Asahi Organic Materials Co., Ltd., the blast furnace slag used was made by JFE Mineral Co., Ltd., and the coal ash used was Fly Ash II manufactured by Chugoku Electric Power Co., Inc. For the paper sludge ash, Eco Soil P manufactured by ETS Japan Co., Ltd. was used. Further, the metal aluminum powder used was manufactured by Yamaishi Metal Co., Ltd.
The cone index was measured as described above according to JIS A1228.
以下、使用した汚泥固化用組成物の配合組成、及び、これらを用いて作製し、温度：２０℃、２０℃の空気中で、３日間及び７日間密閉養生した後の対応する上記汚泥固化体のコーン指数の測定結果を表１―表３に示す。 Hereinafter, the blended composition of the sludge solidifying composition used, and the corresponding sludge solidified body prepared using these and after being hermetically cured for 3 days and 7 days in air at a temperature of 20 ° C. and 20 ° C. The measurement results of the cone index of are shown in Tables 1 to 3.
＜評価＞
以上の結果より、本発明の固化剤は短時間に固化が進行し、固化強度に優れていることが明らかである。すなわち、上記[１]（段落番号[００１４]）に規定する本発明に係る実施例１―２０のすべてにおいて、温度：２０℃で、７日間、密閉養生した後のコーン指数が、いずれも、酸化カルシウムのみを硬化成分とする比較例１、ポルトランドセメントのみを固化剤成分とする比較例２、さらには、酸化カルシウムとポルトランドセメントとの混合物のみを固化剤成分とする比較例３の測定値を上回ることが判った。
<Evaluation>
From the above results, it is clear that the solidifying agent of the present invention proceeds to solidify in a short time and has excellent solidification strength. That is, in all of Examples 1-20 according to the present invention specified in the above [1] (paragraph number [0014]), the cone index after closed curing for 7 days at a temperature of 20 ° C. The measured values of Comparative Example 1 in which only calcium oxide is used as a curing component, Comparative Example 2 in which only Portland cement is used as a solidifying component, and Comparative Example 3 in which only a mixture of calcium oxide and Portland cement is used as a solidifying agent component. It turned out to exceed.
また、特に、配合組成が上記[２]（段落番号[００１４]）の範囲内にある実施例（実施例２−４、７−１０、１２−１４、及び１７−２０）では、密閉養生３日後のコーン指数が２２８ｋＮ／ｍ２以上、密閉養生７日後で２６０ｋＮ／ｍ２以上の高い測定値が得られており、本発明固有の固化剤の優位性が明らかとなっている。一方、組成成分的には、本発明の上記[１]（段落番号[００１４]）の範囲内にあるものの、硫酸アルミニウムに対する酸化カルシウムの添加量が、より多い実施例１及び実施例１１、或いは逆に、硫酸アルミニウムに対する酸化カルシウムの添加量が、より少ない実施例５、６及び実施例１５、１６では、配合組成が上記[２]（段落番号[００１４]）の範囲内にある上記各実施例と対比すると、より低いコーン指数に留まることが判った。 Further, in particular, in Examples (Examples 2-4, 7-10, 12-14, and 17-20) in which the compounding composition is within the range of the above [2] (paragraph number [0014]), the closed curing 3 cone index after day 228kN / m 2 or more, after sealing curing 7 days and 260kN / m 2 higher than the measured value is obtained, the superiority of the present invention specific solidifying agent are revealed. On the other hand, although the composition component is within the range of the above [1] (paragraph number [0014]) of the present invention, the amount of calcium oxide added to aluminum sulfate is larger in Examples 1 and 11 or On the contrary, in Examples 5 and 6 and Examples 15 and 16 in which the amount of calcium oxide added to aluminum sulfate is smaller, the compounding composition is within the range of the above [2] (paragraph number [0014]). In comparison with the example, it was found that the cone index remained lower.
さらに、硫酸アルミニウム、或いは、硫酸鉄（II）の結晶水に着目すると、硫酸アルミニウム・１５水和物及び硫酸鉄（II）・１水和物を用いた実施例１−１０（表１参照）よりも、硫酸アルミニウム（無水物）及び硫酸鉄（II）・７水和物を用いた実施例１１−１８（表２参照）の方が、密閉養生３日後、密閉養生７日後のいずれにおいても、より高いコーン指数の測定値が得られており、特に、実施例２０では、密閉養生７日後のコーン指数が、６５０ｋＮ／ｍ２に到達した。 Furthermore, focusing on aluminum sulfate or water of crystallization of iron (II) sulfate, Example 1-10 using aluminum sulfate / 15hydrate and iron (II) sulfate / monohydrate (see Table 1). Examples 11-18 (see Table 2) using aluminum sulfate (anhydrous) and iron (II) sulfate heptahydrate were more effective than those after 3 days of closed curing and 7 days after closed curing. Higher cone index measurements were obtained, and in particular, in Example 20, the cone index after 7 days of closed curing reached 650 kN / m 2 .
本発明は汚泥固化用組成物に関するもので、特に、汚泥に含まれる重金属等の確実な不溶化と、汚泥固化体への強度付与を同時に行えるため、下水等から発生する都市汚泥等の処理に好適な汚泥固化用組成物として活用できる。さらに、充分な養生と乾燥後の汚泥固化体は、路盤材等の道路補修材等の分野に利用可能である。 The present invention relates to a composition for solidifying sludge, and is particularly suitable for treating urban sludge generated from sewage or the like because it can reliably insolubilize heavy metals contained in sludge and impart strength to the solidified sludge at the same time. Can be used as a sludge solidifying composition. Further, the sludge solidified body after sufficient curing and drying can be used in the field of road repair materials such as roadbed materials.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113149607A (en) * | 2021-04-14 | 2021-07-23 | 天津城建大学 | Sludge brick heavy metal curing agent, sludge brick and preparation method of sludge brick |
| CN113402153A (en) * | 2021-07-19 | 2021-09-17 | 梁政 | Sludge and sludge moisture draining agent |
| CN114394722A (en) * | 2022-01-13 | 2022-04-26 | 北京泾渭环境科技有限公司 | Sludge in-situ solidification construction method |
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| JP2004099688A (en) * | 2002-09-06 | 2004-04-02 | Maeda Corp | Soil improvement method for high moisture soil and soil improver |
| JP2005035868A (en) * | 2003-06-27 | 2005-02-10 | Japan Vam & Poval Co Ltd | Processing method of sludge |
| JP2018038957A (en) * | 2016-09-07 | 2018-03-15 | 太平洋セメント株式会社 | Processing method of mud generated in muddy water shield method |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004099688A (en) * | 2002-09-06 | 2004-04-02 | Maeda Corp | Soil improvement method for high moisture soil and soil improver |
| JP2005035868A (en) * | 2003-06-27 | 2005-02-10 | Japan Vam & Poval Co Ltd | Processing method of sludge |
| JP2018038957A (en) * | 2016-09-07 | 2018-03-15 | 太平洋セメント株式会社 | Processing method of mud generated in muddy water shield method |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113149607A (en) * | 2021-04-14 | 2021-07-23 | 天津城建大学 | Sludge brick heavy metal curing agent, sludge brick and preparation method of sludge brick |
| CN113402153A (en) * | 2021-07-19 | 2021-09-17 | 梁政 | Sludge and sludge moisture draining agent |
| CN114394722A (en) * | 2022-01-13 | 2022-04-26 | 北京泾渭环境科技有限公司 | Sludge in-situ solidification construction method |
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