JP6909878B2 - Organic matter processing method and processing equipment - Google Patents
Organic matter processing method and processing equipment Download PDFInfo
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- JP6909878B2 JP6909878B2 JP2020000237A JP2020000237A JP6909878B2 JP 6909878 B2 JP6909878 B2 JP 6909878B2 JP 2020000237 A JP2020000237 A JP 2020000237A JP 2020000237 A JP2020000237 A JP 2020000237A JP 6909878 B2 JP6909878 B2 JP 6909878B2
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- iron
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- 239000005416 organic matter Substances 0.000 title claims description 26
- 238000003672 processing method Methods 0.000 title claims description 3
- 238000012545 processing Methods 0.000 title description 10
- 239000010802 sludge Substances 0.000 claims description 313
- 238000011282 treatment Methods 0.000 claims description 247
- 238000005273 aeration Methods 0.000 claims description 183
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 95
- 150000002506 iron compounds Chemical class 0.000 claims description 94
- 239000000126 substance Substances 0.000 claims description 72
- 238000005345 coagulation Methods 0.000 claims description 57
- 230000015271 coagulation Effects 0.000 claims description 57
- 239000007789 gas Substances 0.000 claims description 51
- 229910052742 iron Inorganic materials 0.000 claims description 47
- 238000000034 method Methods 0.000 claims description 44
- 239000000701 coagulant Substances 0.000 claims description 41
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 34
- 229910052760 oxygen Inorganic materials 0.000 claims description 34
- 239000001301 oxygen Substances 0.000 claims description 34
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims description 26
- 230000002776 aggregation Effects 0.000 claims description 21
- 238000004220 aggregation Methods 0.000 claims description 19
- 229910021607 Silver chloride Inorganic materials 0.000 claims description 16
- 229910052709 silver Inorganic materials 0.000 claims description 16
- 239000004332 silver Substances 0.000 claims description 16
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 claims description 16
- 230000033116 oxidation-reduction process Effects 0.000 claims description 12
- 230000005764 inhibitory process Effects 0.000 claims 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 54
- 229920000642 polymer Polymers 0.000 description 41
- 208000005156 Dehydration Diseases 0.000 description 35
- 230000018044 dehydration Effects 0.000 description 35
- 238000006297 dehydration reaction Methods 0.000 description 35
- 238000002347 injection Methods 0.000 description 35
- 239000007924 injection Substances 0.000 description 35
- 238000012360 testing method Methods 0.000 description 30
- 238000000855 fermentation Methods 0.000 description 29
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- 238000005063 solubilization Methods 0.000 description 24
- 230000007928 solubilization Effects 0.000 description 24
- 238000003860 storage Methods 0.000 description 22
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- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 18
- 239000002699 waste material Substances 0.000 description 17
- 238000000926 separation method Methods 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 16
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 14
- 230000002401 inhibitory effect Effects 0.000 description 13
- 239000002994 raw material Substances 0.000 description 13
- 238000004519 manufacturing process Methods 0.000 description 12
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 11
- 230000003381 solubilizing effect Effects 0.000 description 11
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 10
- 239000000203 mixture Substances 0.000 description 10
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- CFQYOTZLYKJVKS-UHFFFAOYSA-N 4-[9-(4-carbamimidoylphenoxy)nonoxy]benzenecarboximidamide Chemical compound C1=CC(C(=N)N)=CC=C1OCCCCCCCCCOC1=CC=C(C(N)=N)C=C1 CFQYOTZLYKJVKS-UHFFFAOYSA-N 0.000 description 5
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 5
- 229910021529 ammonia Inorganic materials 0.000 description 5
- 125000000129 anionic group Chemical group 0.000 description 5
- 125000002091 cationic group Chemical group 0.000 description 5
- 229920001577 copolymer Polymers 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- CERQOIWHTDAKMF-UHFFFAOYSA-M Methacrylate Chemical compound CC(=C)C([O-])=O CERQOIWHTDAKMF-UHFFFAOYSA-M 0.000 description 4
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 239000010815 organic waste Substances 0.000 description 4
- 239000010865 sewage Substances 0.000 description 4
- 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 3
- 238000004458 analytical method Methods 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- 125000004985 dialkyl amino alkyl group Chemical group 0.000 description 3
- -1 dimethylaminoethyl Chemical group 0.000 description 3
- 239000004021 humic acid Substances 0.000 description 3
- 239000010806 kitchen waste Substances 0.000 description 3
- 244000005700 microbiome Species 0.000 description 3
- 150000007524 organic acids Chemical class 0.000 description 3
- 238000004065 wastewater treatment Methods 0.000 description 3
- 241000894006 Bacteria Species 0.000 description 2
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000004523 agglutinating effect Effects 0.000 description 2
- 230000004931 aggregating effect Effects 0.000 description 2
- 238000013019 agitation Methods 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- 229920006318 anionic polymer Polymers 0.000 description 2
- 229920006317 cationic polymer Polymers 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000004332 deodorization Methods 0.000 description 2
- 238000006477 desulfuration reaction Methods 0.000 description 2
- 230000023556 desulfurization Effects 0.000 description 2
- 230000029087 digestion Effects 0.000 description 2
- 238000007865 diluting Methods 0.000 description 2
- 238000011038 discontinuous diafiltration by volume reduction Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 229960002089 ferrous chloride Drugs 0.000 description 2
- 239000010794 food waste Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 2
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 2
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical compound CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002894 organic compounds Chemical class 0.000 description 2
- 239000010801 sewage sludge Substances 0.000 description 2
- 210000002700 urine Anatomy 0.000 description 2
- 239000002351 wastewater Substances 0.000 description 2
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- JKNCOURZONDCGV-UHFFFAOYSA-N 2-(dimethylamino)ethyl 2-methylprop-2-enoate Chemical compound CN(C)CCOC(=O)C(C)=C JKNCOURZONDCGV-UHFFFAOYSA-N 0.000 description 1
- DPBJAVGHACCNRL-UHFFFAOYSA-N 2-(dimethylamino)ethyl prop-2-enoate Chemical compound CN(C)CCOC(=O)C=C DPBJAVGHACCNRL-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 239000002028 Biomass Substances 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 238000010306 acid treatment Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 230000001112 coagulating effect Effects 0.000 description 1
- 239000002361 compost Substances 0.000 description 1
- 238000011437 continuous method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001877 deodorizing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000001079 digestive effect Effects 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 239000003651 drinking water Substances 0.000 description 1
- 235000020188 drinking water Nutrition 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 239000008394 flocculating agent Substances 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 229920006158 high molecular weight polymer Polymers 0.000 description 1
- 238000004128 high performance liquid chromatography Methods 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- 239000008235 industrial water Substances 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 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 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 1
- 239000004310 lactic acid Substances 0.000 description 1
- 235000014655 lactic acid Nutrition 0.000 description 1
- 238000005339 levitation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- FQPSGWSUVKBHSU-UHFFFAOYSA-N methacrylamide Chemical compound CC(=C)C(N)=O FQPSGWSUVKBHSU-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 230000014508 negative regulation of coagulation Effects 0.000 description 1
- 230000001546 nitrifying effect Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000009291 secondary effect Effects 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 230000001568 sexual effect Effects 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 238000004017 vitrification Methods 0.000 description 1
Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
- B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
- C02F11/143—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using inorganic substances
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/02—Biological treatment
- C02F11/04—Anaerobic treatment; Production of methane by such processes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/14—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents
- C02F11/147—Treatment of sludge; Devices therefor by de-watering, drying or thickening with addition of chemical agents using organic substances
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/34—Biological treatment of water, waste water, or sewage characterised by the microorganisms used
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E50/00—Technologies for the production of fuel of non-fossil origin
- Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Hydrology & Water Resources (AREA)
- Organic Chemistry (AREA)
- Water Supply & Treatment (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Microbiology (AREA)
- Molecular Biology (AREA)
- Health & Medical Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Biodiversity & Conservation Biology (AREA)
- Treatment Of Sludge (AREA)
- Processing Of Solid Wastes (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Description
本発明は、有機物の処理方法及び処理装置に関し、特に有機物の嫌気性処理方法及び処理装置に関する。 The present invention relates to a method and an apparatus for treating an organic substance, and more particularly to an anaerobic treatment method and an apparatus for an organic substance.
メタン発酵は、嫌気性処理、嫌気性消化とも呼ばれている。本願明細書及び特許請求の範囲において「嫌気性処理」とはメタン発酵及び嫌気性消化を含み、有機物を嫌気性処理した汚泥を「嫌気性処理汚泥」と称する。 Methane fermentation is also called anaerobic treatment or anaerobic digestion. In the present specification and claims, "anaerobic treatment" includes methane fermentation and anaerobic digestion, and sludge obtained by anaerobicly treating organic substances is referred to as "anaerobic treated sludge".
食品残渣、食品製造残渣、生ごみ、各種汚泥などの有機物を対象としたメタン発酵は、有機物を嫌気性処理し、廃棄物を減量化するとともに、廃棄物からメタンガスを発生させ、エネルギーを回収できる技術であり、環境負荷を低減できる技術として注目されている。しかし、発生する嫌気性処理汚泥は、難脱水性汚泥であることが多く、嫌気性処理後の汚泥脱水処理では、凝集剤を多量に必要とし、脱水ケーキの含水率も高い。また、発生する嫌気性処理汚泥は、高価なアミジン系高分子凝集剤でしか凝集させることができない場合があり、運転コストが高いという問題がある。 Methane fermentation for organic substances such as food residues, food production residues, kitchen waste, and various sludges can anaerobically treat organic substances, reduce the amount of waste, and generate methane gas from the waste to recover energy. It is a technology and is attracting attention as a technology that can reduce the environmental load. However, the generated anaerobic treated sludge is often poorly dehydrated sludge, and the sludge dehydration treatment after the anaerobic treatment requires a large amount of coagulant and has a high water content of the dehydrated cake. Further, the generated anaerobic treated sludge may be agglomerated only by an expensive amidine-based polymer flocculant, and there is a problem that the operating cost is high.
このため、低廉な運転コストで、メタン発酵でメタンガスを効率的に回収するとともに、発生する嫌気性処理汚泥を効率的に脱水する技術が必要とされている。
嫌気性処理汚泥の脱水性を改善する方法に関連する技術として、下記のような先行技術が知られている。
Therefore, there is a need for a technique for efficiently recovering methane gas by methane fermentation and efficiently dehydrating the generated anaerobic treated sludge at a low operating cost.
The following prior art is known as a technique related to a method for improving the dehydration property of anaerobic sludge.
特許文献１には、有機性廃棄物をメタン発酵して得られる発酵残液およびその他の嫌気性有機化合物含有液をｐＨ５．５以下に調整するとともに酸化剤と接触させる液処理工程を含むことを特徴とする、発酵残液およびその他の嫌気性有機化合物含有液の処理方法が記載されている。 Patent Document 1 includes a liquid treatment step of adjusting the pH of the fermentation residue obtained by methane fermentation of organic waste and other anaerobic organic compound-containing liquids to 5.5 or less and bringing them into contact with an oxidizing agent. A method for treating a fermentation residue and other anaerobic organic compound-containing liquids, which is characteristic, is described.
特許文献２には、下水汚泥、厨芥などメタン発酵が可能な有機性廃棄物を嫌気性消化処理し、消化残物を酸素含有ガスで曝気処理したのち機械脱水し、該脱水ケーキを、前記有機性廃棄物の発生源である有機性排水の生物処理工程の曝気槽へ空気を供給する曝気ブロアの吐出空気と直接接触させ、その保有熱によって乾燥することを特徴とする有機性廃棄物の処理方法が記載されている。 In Patent Document 2, organic waste capable of methane fermentation such as sewage sludge and kitchen waste is anaerobic digested, and the digested residue is aerated with an oxygen-containing gas and then mechanically dehydrated. Treatment of organic waste characterized by direct contact with the discharged air of an aeration blower that supplies air to the aeration tank in the biological treatment process of organic wastewater, which is the source of sexual waste, and drying by the heat possessed by the aeration blower. The method is described.
特許文献３には、嫌気性消化汚泥に曝気を行った後、余剰汚泥を混合し、得られた混合汚泥に金属塩を添加し、次いで両性有機高分子凝集剤を添加して凝集処理し、凝集汚泥を脱水機で脱水することを特徴とする嫌気性消化汚泥の脱水方法が記載されている。 In Patent Document 3, after aeration of anaerobic digested sludge, excess sludge is mixed, a metal salt is added to the obtained mixed sludge, and then an amphoteric organic polymer flocculant is added for coagulation treatment. A method for dehydrating anaerobic digested sludge, which comprises dehydrating agglomerated sludge with a dehydrator, is described.
本発明は、有機物を効率的に嫌気性処理するとともに、嫌気性処理汚泥を効率的に凝集させることができる有機物の処理方法及び処理装置を提供することを目的とする。 An object of the present invention is to provide a method and an apparatus for treating an organic substance, which can efficiently treat an organic substance in an anaerobic manner and efficiently agglomerate the anaerobic treated sludge.
本発明は、有機物の嫌気性処理において、嫌気性処理工程の前、もしくは嫌気性処理工程において鉄化合物を注入し、鉄化合物を含有する嫌気性処理汚泥を形成させ、次いで鉄化合物を含有する嫌気性処理汚泥に酸素含有気体を接触させて鉄（II）が酸化された鉄（III）を含有する曝気処理汚泥を形成させ、次いで鉄（III）を含有する曝気処理汚泥に凝集剤を注入して凝集させた後、脱水処理することを特徴とする。 In the anaerobic treatment of organic substances, the present invention injects an iron compound before the anaerobic treatment step or in the anaerobic treatment step to form an anaerobic treated sludge containing an iron compound, and then anaerobic containing an iron compound. Oxygen-containing gas is brought into contact with the sex-treated sludge to form an aerated-treated sludge containing iron (III) in which iron (II) is oxidized, and then a coagulant is injected into the aerated-treated sludge containing iron (III). It is characterized in that it is agglomerated and then dehydrated.
具体体には下記態様が本発明によって提供される。
［１］有機物を嫌気性処理し、嫌気性処理汚泥を形成させる嫌気性処理工程と、
嫌気性処理汚泥に酸素含有気体を接触させ、曝気処理汚泥を形成させる曝気処理工程と、
曝気処理汚泥に凝集剤を注入し、凝集汚泥を形成させる凝集工程を有し、
前記嫌気性処理工程の前、もしくは前記嫌気性処理工程において、前記有機物に鉄化合物を注入し、
前記曝気処理工程において、前記曝気処理汚泥の酸化還元電位（銀／塩化銀電極を基準とした酸化還元電位）を−１００ｍＶ以下に制御し、鉄化合物を含有する嫌気性処理汚泥と酸素含有気体とを接触させることにより、嫌気性処理汚泥に含まれる鉄（II）を酸化させ、
前記凝集工程で酸化された鉄（III）を凝集剤として利用することを特徴とする有機物の処理方法。
［２］前記嫌気性処理工程において鉄を注入した後の汚泥に含まれる鉄の濃度は、鉄換算で１００ｍｇ／Ｌ以上であることを特徴とする［１］に記載の有機物の処理方法。
［３］前記曝気処理工程において、前記曝気処理汚泥の溶存酸素濃度を１．０ｍｇ／Ｌ以下に制御することを特徴とする［１］又は［２］に記載の有機物の処理方法。
［４］前記脱水工程からの脱水分離液に含まれるアンモニアを硝化する硝化工程をさらに含み、
当該硝化工程からの排気ガスを前記曝気処理工程における酸素含有気体として再利用することを特徴とする［１］〜［３］のいずれか１に記載の有機物の処理方法。
［５］前記嫌気性処理汚泥は、２５ｇ／Ｌ以上のＴＳ濃度と、当該ＴＳ濃度よりも５ｇ／Ｌ以上低いＳＳ濃度と、を有することを特徴とする［１］〜［４］のいずれか１に記載の有機物の処理方法。
［６］有機物に鉄化合物を注入する鉄化合物注入手段と、
鉄（II）の共存下で有機物を嫌気性処理し、嫌気性処理汚泥を形成させる嫌気性処理槽と、
酸化還元電位測定装置を有し、当該嫌気性処理汚泥に酸素含有気体を接触させ、鉄（II）を鉄（III）に酸化させて、鉄（III）を含む曝気処理汚泥を形成させる曝気槽と、
当該曝気処理汚泥に凝集剤を注入し、凝集汚泥を形成させる凝集槽と、
当該凝集汚泥を脱水する脱水装置と、
当該脱水装置からの脱水分離液に含まれるアンモニアを硝化する硝化槽と、
当該硝化槽からの排気ガスを当該曝気槽に供給する酸素含有気体供給配管を具備することを特徴とする、［１］〜［５］のいずれか１に記載の有機物の処理方法を実施する処理装置。
［７］前記鉄化合物注入手段は、前記嫌気性処理槽、又は前記嫌気性処理槽の前段に設けられている有機物貯槽、可溶化槽及び可溶化物貯槽から選択される少なくとも１の槽、又は当該少なくとも１の槽と前記嫌気性処理槽を連結する配管、又は当該有機物貯槽、可溶化槽及び可溶化物貯槽の少なくとも２の槽の間を連結する配管のいずれかもしくは２以上に設けられていることを特徴とする［６］に記載の処理装置。
The following aspects are provided in the concrete body by the present invention.
[1] An anaerobic treatment step of anaerobic treating an organic substance to form an anaerobic treated sludge,
An aeration treatment process in which an oxygen-containing gas is brought into contact with the anaerobic treatment sludge to form an aeration treatment sludge,
It has a coagulation step in which a coagulant is injected into aeration-treated sludge to form coagulated sludge.
Before the anaerobic treatment step, or in the anaerobic treatment step, an iron compound is injected into the organic substance.
In the aeration treatment step, the redox potential (oxidation-reduction potential based on the silver / silver chloride electrode) of the aeration-treated sludge is controlled to -100 mV or less, and the anaerobic treated sludge containing an iron compound and the oxygen-containing gas are combined. Oxidizes iron (II) contained in anaerobic treated sludge by contacting
A method for treating an organic substance, which comprises using iron (III) oxidized in the coagulation step as a coagulant.
[2] The method for treating an organic substance according to [1], wherein the concentration of iron contained in the sludge after injecting iron in the anaerobic treatment step is 100 mg / L or more in terms of iron.
[3] The method for treating an organic substance according to [1] or [2], wherein the dissolved oxygen concentration of the aeration-treated sludge is controlled to 1.0 mg / L or less in the aeration treatment step.
[4] Further includes a nitrification step of nitrifying ammonia contained in the dehydration separation liquid from the dehydration step.
The method for treating an organic substance according to any one of [1] to [3], wherein the exhaust gas from the nitrification step is reused as an oxygen-containing gas in the aeration treatment step.
[5] The anaerobic treated sludge has a TS concentration of 25 g / L or more and an SS concentration of 5 g / L or more lower than the TS concentration, whichever is one of [1] to [4]. The method for treating an organic substance according to 1.
[6] An iron compound injection means for injecting an iron compound into an organic substance,
An anaerobic treatment tank that anaerobicly treats organic matter in the coexistence of iron (II) to form anaerobic treatment sludge,
An aeration tank having an oxidation-reduction potential measuring device, in which an oxygen-containing gas is brought into contact with the anaerobic treated sludge to oxidize iron (II) to iron (III) to form an aerated treated sludge containing iron (III). When,
A coagulation tank that injects a coagulant into the aeration-treated sludge to form coagulation sludge,
A dehydrator that dehydrates the aggregated sludge,
A nitrification tank that nitrifies the ammonia contained in the dehydration separation solution from the dehydrator,
The process for carrying out the method for treating an organic substance according to any one of [1] to [5], which comprises an oxygen-containing gas supply pipe for supplying the exhaust gas from the nitrification tank to the aeration tank. Device.
[7] The iron compound injection means is an anaerobic treatment tank, or at least one tank selected from an organic matter storage tank, a solubilization tank, and a solubilized product storage tank provided in front of the anaerobic treatment tank, or. Provided in any or two or more of the pipes connecting the at least one tank and the anaerobic treatment tank, or the pipes connecting at least two tanks of the organic matter storage tank, the solubilization tank and the solubilized substance storage tank. The processing apparatus according to [6].
本発明により、有機物を効率的に嫌気性処理するとともに、嫌気性処理汚泥を効率的に凝集させることができる。また、副次的な効果として、排水処理、脱硫処理、脱臭処理への負荷を低減できる。より詳しくは下記のような効果がある。
（１）鉄化合物が注入された有機物を嫌気性処理することにより、有機物の安定的な嫌気性処理が可能となり、減容化率の増加及びメタンガス発生量の増加が可能となる。
（２）鉄化合物が注入された有機物を嫌気処理することにより、有機物に含まれる硫黄分と鉄が結合して、硫化水素の発生を抑制することができ、後段の脱硫処理や脱臭処理における負荷を低減することが可能となる。
（３）曝気処理工程で嫌気性処理汚泥と酸素を接触させることにより、嫌気性処理汚泥中に含まれる鉄を酸化させ、凝集剤として利用することにより、後段の凝集工程における凝集剤の注入量を削減することが可能となる。
（４）曝気処理工程において嫌気性処理汚泥に含有されている凝集阻害物質（例えば、多糖類、タンパク質、糖タンパク質、核酸、リン脂質、フミン酸などの高分子物質）を分解させるので、高価なアミジン系高分子凝集剤でしか凝集させることができない嫌気性処理汚泥に対して、安価な非アミジン系高分子凝集剤又はアミジン系高分子凝集剤に安価な非アミジン系高分子凝集剤を混合したブレンド品を凝集工程で使用でき、凝集コストを低減することが可能となる。
（５）曝気処理工程において嫌気性処理汚泥と酸素を接触させることにより、嫌気性処理汚泥に含有される凝集阻害物質（例えば、多糖類、タンパク質、糖タンパク質、核酸、リン脂質、フミン酸などの高分子物質）の分解が可能となり、後段の凝集工程における凝集剤の注入量を削減でき、さらに後段の脱水工程により得られる脱水ケーキの含水率を低減することが可能となる。
（６）曝気処理工程において嫌気性処理汚泥と酸素を接触させることにより、嫌気性処理汚泥に溶存している炭酸ガスを除去し、後段の凝集工程で凝集剤を注入した際の発泡現象を抑制することが可能となる。
（７）後段の脱水工程において分離した脱水分離液を排水処理する場合、曝気処理工程において有機物成分（ＢＯＤ成分、ＣＯＤ成分など）の一部が分解されているので、脱水分離液の排水処理における有機物負荷を低減することが可能となる。
（８）脱水工程からの脱水分離液に含まれるアンモニアを硝化する硝化工程からの排気ガスを曝気処理工程における酸素含有気体として再利用する場合には、硝化工程からの排出ガス量を削減することが可能となると共に、処理施設全体のエネルギー損失を削減することができる。
According to the present invention, organic matter can be efficiently anaerobically treated and anaerobic treated sludge can be efficiently aggregated. In addition, as a secondary effect, the load on wastewater treatment, desulfurization treatment, and deodorization treatment can be reduced. More specifically, it has the following effects.
(1) By anaerobic treating an organic substance into which an iron compound is injected, stable anaerobic treatment of the organic substance becomes possible, and the volume reduction rate and the amount of methane gas generated can be increased.
(2) By anaerobically treating the organic matter into which the iron compound is injected, the sulfur content contained in the organic matter and iron can be combined to suppress the generation of hydrogen sulfide, and the load in the subsequent desulfurization treatment and deodorization treatment can be suppressed. Can be reduced.
(3) By bringing anaerobic treated sludge into contact with oxygen in the aeration treatment step, iron contained in the anaerobic treated sludge is oxidized and used as a coagulant, so that the amount of the coagulant injected in the coagulation step in the subsequent stage. Can be reduced.
(4) It is expensive because it decomposes aggregation-inhibiting substances (for example, polymer substances such as polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, and fumic acids) contained in anaerobic treated sludge in the aeration treatment step. For anaerobic treated sludge that can only be aggregated with an amidin-based polymer flocculant, an inexpensive non-amidine polymer flocculant or an inexpensive non-amidine polymer flocculant is mixed with an inexpensive non-amidine polymer flocculant. The blended product can be used in the coagulation step, and the coagulation cost can be reduced.
(5) By bringing anaerobic treated sludge into contact with oxygen in the aeration treatment step, aggregation-inhibiting substances (for example, polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, fumic acid, etc.) contained in the anaerobic treated sludge can be produced. The polymer substance) can be decomposed, the injection amount of the flocculant in the coagulation step in the subsequent stage can be reduced, and the water content of the dehydrated cake obtained in the dewatering step in the subsequent stage can be reduced.
(6) By bringing anaerobic treated sludge into contact with oxygen in the aeration treatment step, carbon dioxide gas dissolved in the anaerobic treated sludge is removed, and the foaming phenomenon when the coagulant is injected in the coagulation step in the subsequent stage is suppressed. It becomes possible to do.
(7) When the dehydration separation liquid separated in the subsequent dehydration step is treated with wastewater, a part of the organic matter components (BOD component, COD component, etc.) is decomposed in the aeration treatment step, so that in the wastewater treatment of the dehydration separation liquid. It is possible to reduce the organic matter load.
(8) When the exhaust gas from the nitrification step that nitrifies the ammonia contained in the dehydration separation solution from the dehydration step is reused as the oxygen-containing gas in the aeration treatment step, the amount of exhaust gas from the nitrification step should be reduced. It is possible to reduce the energy loss of the entire processing facility.
以下、添付図面を参照しながら本発明を詳細に説明する。
本発明の処理方法は、嫌気性処理工程において処理される有機物には鉄化合物が注入されており、鉄（II）の共存下で有機物を嫌気性処理し、形成される嫌気性処理汚泥は鉄（II）を含有し、続く曝気処理工程において、曝気処理汚泥の酸化還元電位（銀／塩化銀電極を基準とした酸化還元電位）を−１００ｍＶ以下に制御し、鉄化合物を含有する嫌気性処理汚泥と酸素含有気体とを接触させることにより、嫌気性処理汚泥に含まれる鉄（II）を酸化させ、後段の凝集工程で酸化された鉄（III）を凝集剤として利用することを特徴とする。
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
In the treatment method of the present invention, an iron compound is injected into the organic substance to be treated in the anaerobic treatment step, and the organic substance is anaerobically treated in the coexistence of iron (II), and the anaerobic treated sludge formed is iron. In the subsequent aeration treatment step containing (II), the oxidation-reduction potential (oxidation-reduction potential based on the silver / silver chloride electrode) of the aeration-treated sludge is controlled to -100 mV or less, and an anaerobic treatment containing an iron compound is performed. It is characterized in that iron (II) contained in anaerobic treated sludge is oxidized by bringing the sludge into contact with an oxygen-containing gas, and iron (III) oxidized in the subsequent coagulation step is used as a coagulant. ..
図１〜図５は、嫌気性処理工程において有機物に鉄化合物を注入する態様を示し、図６〜図９は、嫌気性処理工程の前段である配管、可溶化槽、又は可溶化貯槽において有機物に鉄化合物を注入する態様を示す。 1 to 5 show an embodiment in which an iron compound is injected into an organic substance in an anaerobic treatment step, and FIGS. 6 to 9 show an organic substance in a pipe, a solubilization tank, or a solubilization storage tank which is the first stage of the anaerobic treatment step. An aspect of injecting an iron compound into the body is shown.
まず、図１〜図５に基づいて本発明の有機物の処理方法を説明する。図１及び図３に示すように、
（１）有機物を嫌気性処理し、嫌気性処理汚泥を形成させる嫌気性処理工程と、
（２）嫌気性処理汚泥に酸素含有気体を接触させ、曝気処理汚泥を形成させる曝気処理工程と、
（３）曝気処理汚泥に凝集剤を注入し、凝集汚泥を形成させる凝集工程を有し、
前記嫌気性処理工程において有機物に鉄化合物を注入し、
前記曝気処理工程において、前記曝気処理汚泥の酸化還元電位（銀／塩化銀電極を基準とした酸化還元電位）を−１００ｍＶ以下に制御し、鉄化合物を含有する嫌気性処理汚泥と酸素含有気体とを接触させることにより、嫌気性処理汚泥に含まれる鉄（II）を酸化させ、前記凝集工程で酸化された鉄（III）を凝集剤として利用する。
First, the method for treating an organic substance of the present invention will be described with reference to FIGS. 1 to 5. As shown in FIGS. 1 and 3,
(1) An anaerobic treatment step of anaerobic treating organic substances to form anaerobic treated sludge, and
(2) An aeration treatment step in which an oxygen-containing gas is brought into contact with the anaerobic treatment sludge to form an aeration treatment sludge.
(3) It has a coagulation step of injecting a coagulant into aeration-treated sludge to form coagulated sludge.
In the anaerobic treatment step, an iron compound is injected into the organic substance,
In the aeration treatment step, the oxidation-reduction potential (oxidation-reduction potential based on the silver / silver chloride electrode) of the aeration-treated sludge is controlled to -100 mV or less, and the anaerobic-treated sludge containing an iron compound and the oxygen-containing gas are used. Is brought into contact with the iron (II) contained in the anaerobic treated sludge, and the iron (III) oxidized in the coagulation step is used as a coagulant.
図２、図４及び図５に示すように、凝集工程後に脱水処理工程を含み、さらに脱水処理工程後の硝化工程を含み得る。
次に、図６〜図９に基づいて有機物への鉄化合物の注入時点を説明する。図６は嫌気性処理工程の前段の配管にて有機物に鉄化合物を注入する態様であり、図７は嫌気性処理工程の前段の可溶化工程にて有機物に鉄化合物を注入する態様であり、図８及び図９は可溶化工程後で嫌気性処理工程前に可溶化物を貯蔵する工程にて有機物に鉄化合物を注入する態様である。鉄化合物の注入時点を除いて、図６〜図９の態様に図１〜図４に示す凝集工程及び脱水工程を任意に組み合わせることができる。
As shown in FIGS. 2, 4 and 5, a dehydration treatment step may be included after the aggregation step, and a nitrification step after the dehydration treatment step may be further included.
Next, the time point of injection of the iron compound into the organic substance will be described with reference to FIGS. 6 to 9. FIG. 6 shows a mode in which the iron compound is injected into the organic substance in the piping before the anaerobic treatment step, and FIG. 7 shows a mode in which the iron compound is injected into the organic substance in the solubilization step in the stage before the anaerobic treatment step. 8 and 9 show a mode in which the iron compound is injected into the organic substance in the step of storing the solubilized matter after the solubilization step and before the anaerobic treatment step. Except for the time of injection of the iron compound, the aggregation step and the dehydration step shown in FIGS. 1 to 4 can be arbitrarily combined with the embodiments shown in FIGS. 6 to 9.
以下、各工程について説明する。
（１）鉄化合物注入工程
嫌気性処理工程又は嫌気性処理工程の前に、有機物に鉄化合物を注入し、嫌気性処理工程にて鉄（II）の共存下で有機物を嫌気性処理することができるように準備する。有機物への鉄化合物の注入は、嫌気性処理工程又は嫌気性処理工程の前になされていれば特に制限されず、嫌気性処理槽に供給される前の有機物又は有機物貯槽に貯蔵されている有機物に鉄化合物を直接注入してもよく、嫌気性処理槽において有機物に鉄化合物を注入してもよく（図１）、嫌気性処理槽に有機物を供給する配管に鉄化合物を注入してもよく（図６）、嫌気性処理槽の前段である可溶化槽（図７）又は可溶化貯槽（図８及び図９）に鉄化合物を注入してもよい。
Hereinafter, each step will be described.
(1) Iron compound injection step Before the anaerobic treatment step or the anaerobic treatment step, the iron compound can be injected into the organic substance, and the organic substance can be anaerobically treated in the coexistence of iron (II) in the anaerobic treatment step. Be prepared to do it. The injection of the iron compound into the organic matter is not particularly limited as long as it is performed before the anaerobic treatment step or the anaerobic treatment step, and the organic matter before being supplied to the anaerobic treatment tank or the organic matter stored in the organic matter storage tank. The iron compound may be directly injected into the anaerobic treatment tank, the iron compound may be injected into the organic matter in the anaerobic treatment tank (Fig. 1), or the iron compound may be injected into the pipe for supplying the organic matter to the anaerobic treatment tank. (FIG. 6), the iron compound may be injected into the solubilization tank (FIG. 7) or the solubilization storage tank (FIG. 8 and 9), which is the first stage of the anaerobic treatment tank.
可溶化処理を行う可溶化工程は、嫌気性環境下、反応温度２５〜７０℃、ｐＨ３〜６、水理学的滞留時間（ＨＲＴ）０．５日〜５日で、完全混合型発酵装置で行うことが好ましい。特に、有機物の種類によっては固形物の可溶化段階が反応律速となりやすいことから、反応温度を３５〜７０℃の高温反応でＨＲＴを３日〜５日で行うことが好ましい。高温反応による熱処理と好熱性生物による可溶化が同時に達成される。さらに、ＨＲＴ制御することによって、通常は高い増殖速度能を有する嫌気性微生物を優占化することができ、嫌気的可溶化処理が可能となる。また、反応温度が３５〜７０℃の高温反応にて可溶化処理を行うことで、ＴＳ濃度１０〜１５％の高濃度有機性廃棄物に対しても比較的低粘度条件で容易に混合撹拌が可能となる。可溶化処理工程において、通常、有機物の可溶化物は速やかに加水分解されたり酸発酵したりするので、乳酸発酵や酸発酵を主体とする嫌気性発酵がほぼ同時に進行することになる。したがって、可溶化処理工程では可溶化菌と酸発酵菌とが優占的に共存する発酵環境となる。 The solubilization step for solubilization is performed in a completely mixed fermentation apparatus under an anaerobic environment with a reaction temperature of 25 to 70 ° C., a pH of 3 to 6, and a hydraulic residence time (HRT) of 0.5 to 5 days. Is preferable. In particular, depending on the type of organic substance, the solubilization step of the solid substance tends to be rate-determining, so it is preferable to carry out HRT in 3 to 5 days with a high-temperature reaction at a reaction temperature of 35 to 70 ° C. Heat treatment by high temperature reaction and solubilization by thermophilic organisms are achieved at the same time. Furthermore, by controlling HRT, anaerobic microorganisms that normally have a high growth rate ability can be dominated, and anaerobic solubilization treatment becomes possible. Further, by performing the solubilization treatment in a high temperature reaction having a reaction temperature of 35 to 70 ° C., even high-concentration organic waste having a TS concentration of 10 to 15% can be easily mixed and stirred under relatively low viscosity conditions. It will be possible. In the solubilization treatment step, solubilized organic substances are usually rapidly hydrolyzed or acid-fermented, so that anaerobic fermentation mainly composed of lactic acid fermentation and acid fermentation proceeds almost at the same time. Therefore, in the solubilization treatment step, the fermentation environment is such that the solubilized bacteria and the acid fermenting bacteria coexist predominantly.
可溶化処理された可溶化物は嫌気性処理前に貯蔵されることが多い。可溶化物貯槽に貯蔵されている可溶化物に鉄化合物を注入することで、可溶化物である有機物中に鉄化合物を均一に分散させることができる。 Solubilized solubilized products are often stored prior to anaerobic treatment. By injecting the iron compound into the solubilized product stored in the solubilized product storage tank, the iron compound can be uniformly dispersed in the organic substance which is the solubilized product.
有機物を直接、又は上記の可溶化槽もしくは可溶化物貯槽から嫌気性処理槽に供給するための配管、あるいは嫌気性処理槽に、鉄化合物を注入してもよい。これらの配管又は嫌気性処理槽に鉄化合物を注入する場合には、嫌気性処理汚泥に含まれる鉄濃度を直接的に制御することができる。 The iron compound may be injected directly into the pipe for supplying the organic substance directly from the above-mentioned solubilization tank or anaerobic treatment tank to the anaerobic treatment tank, or into the anaerobic treatment tank. When the iron compound is injected into these pipes or the anaerobic treatment tank, the iron concentration contained in the anaerobic treatment sludge can be directly controlled.
有機物に対する鉄化合物の注入量は、嫌気性処理工程で処理される汚泥に含まれる鉄の濃度を鉄換算で１００ｍｇ／Ｌ以上、好ましくは１００〜６００ｍｇ／Ｌ、より好ましくは１５０〜５００ｍｇ／Ｌ、特に好ましくは１５０〜４５０ｍｇ／Ｌとなるように調整する。嫌気性処理工程の前に有機物に鉄化合物を注入することにより、有機物の嫌気性処理が促進され、減容化率が増加するとともに、メタンガス回収率が向上する。 The amount of the iron compound injected into the organic matter is such that the concentration of iron contained in the sludge treated in the anaerobic treatment step is 100 mg / L or more in terms of iron, preferably 100 to 600 mg / L, and more preferably 150 to 500 mg / L. Particularly preferably, it is adjusted to 150 to 450 mg / L. By injecting an iron compound into an organic substance before the anaerobic treatment step, the anaerobic treatment of the organic substance is promoted, the volume reduction rate is increased, and the methane gas recovery rate is improved.
本発明において嫌気性処理工程又は嫌気性処理工程の前に有機物に注入する鉄化合物としては、塩化第二鉄、塩化第一鉄、硫酸第二鉄、硫酸第一鉄、ポリ硫酸第二鉄、ポリ硫酸第一鉄などが挙げられる。 In the present invention, examples of the iron compound to be injected into the organic substance before the anaerobic treatment step or the anaerobic treatment step include ferric chloride, ferrous chloride, ferric sulfate, ferrous sulfate, polyferrous sulfate. Examples include ferrous polysulfate.
（２）嫌気性処理工程
嫌気性処理工程では、有機物を嫌気性処理し、嫌気性微生物の働きにより有機物を嫌気性処理汚泥にして減容化するとともに、メタンガスを発生させる。本発明において、嫌気性処理工程において処理される有機物には鉄化合物が注入されており、鉄（II）の共存下で有機物を嫌気性処理し、形成される嫌気性処理汚泥は鉄（II）を含有するものとなる。
(2) Anaerobic treatment step In the anaerobic treatment step, the organic matter is anaerobically treated, and the organic matter is converted into an anaerobic treatment sludge by the action of anaerobic microorganisms to reduce the volume and generate methane gas. In the present invention, an iron compound is injected into the organic matter treated in the anaerobic treatment step, and the anaerobic treated sludge formed by anaerobic treating the organic matter in the coexistence of iron (II) is iron (II). Will be contained.
嫌気性処理工程の運転条件は、処理温度３０〜６０℃、滞留日数（ＨＲＴ）１２〜４０日が一般的である。嫌気性処理には、完全混合型（液状物を撹拌しながら嫌気性処理する）や乾式メタン発酵（半固形物を撹拌しながら嫌気性処理する）などがあるが、処理形態は特に限定されない。 The operating conditions of the anaerobic treatment step are generally a treatment temperature of 30 to 60 ° C. and a residence period (HRT) of 12 to 40 days. The anaerobic treatment includes a completely mixed type (anaerobic treatment while stirring a liquid substance) and a dry methane fermentation (anaerobic treatment while stirring a semi-solid substance), but the treatment form is not particularly limited.
嫌気性処理で処理対象となる有機物としては、食品残渣、食品製造残渣、生ごみ、各種汚泥などが挙げられる。各種汚泥としては、下水汚泥（初沈汚泥、余剰汚泥、混合生汚泥）、農業集落排水汚泥、し尿汚泥（生し尿、浄化槽汚泥）、各種排水処理から発生する汚泥などが挙げられる。また、上記の有機物を酸処理、アルカリ処理、熱処理、酸発酵処理などにより可溶化した可溶化物も嫌気性処理の処理対象とすることができる。 Examples of organic substances to be treated in the anaerobic treatment include food residues, food production residues, kitchen waste, and various sludges. Examples of various sludges include sewage sludge (initially settled sludge, surplus sludge, mixed raw sludge), agricultural settlement drainage sludge, urine sludge (raw urine, septic tank sludge), and sludge generated from various wastewater treatments. Further, a solubilized product obtained by solubilizing the above organic matter by acid treatment, alkali treatment, heat treatment, acid fermentation treatment or the like can also be treated for anaerobic treatment.
嫌気性処理工程で形成される嫌気性処理汚泥は、２５ｇ／Ｌ以上のＴＳ濃度と、該ＴＳ濃度よりも５ｇ／Ｌ以上低いＳＳ濃度と、を有することが好ましい。より好ましくは、ＴＳ濃度が２５〜６０ｇ／Ｌ、さらにより好ましくは、ＴＳ濃度が３０〜４５ｇ／Ｌを有する嫌気性処理汚泥である。また、より好ましくは、ＴＳ濃よりも１０ｇ／Ｌ以上低いＳＳ濃度を有する嫌気性処理汚泥である。さらにより好ましくは、ＴＳ濃度よりも１５ｇ／Ｌ以上低いＳＳ濃度を有する嫌気性処理汚泥である。また、嫌気性処理工程で形成される嫌気性処理汚泥の粘度は、好ましくは２００〜１５００ｍＰａ・ｓであり、より好ましくは３００〜１０００ｍＰａ・ｓである。なお、ＴＳ、ＳＳは、それぞれ全蒸発残留物、懸濁物質を意味し、ＴＳ及びＳＳの分析はＪＩＳ Ｋ−０１０２に準拠した。また、粘度は、Ｂ型回転粘度計を使用し、３５℃、６０ｒｐｍで測定した値である。 The anaerobic treated sludge formed in the anaerobic treatment step preferably has a TS concentration of 25 g / L or more and an SS concentration of 5 g / L or more lower than the TS concentration. More preferably, it is an anaerobic treated sludge having a TS concentration of 25 to 60 g / L, and even more preferably a TS concentration of 30 to 45 g / L. Further, more preferably, it is an anaerobic treated sludge having an SS concentration 10 g / L or more lower than the TS concentration. Even more preferably, it is an anaerobic treated sludge having an SS concentration that is 15 g / L or more lower than the TS concentration. The viscosity of the anaerobic treated sludge formed in the anaerobic treatment step is preferably 200 to 1500 mPa · s, and more preferably 300 to 1000 mPa · s. In addition, TS and SS mean total evaporation residue and suspended solids, respectively, and the analysis of TS and SS was based on JIS K-012. The viscosity is a value measured at 35 ° C. and 60 rpm using a B-type rotational viscometer.
（３）曝気処理工程
本発明によれば、嫌気性処理工程において、鉄化合物を含有する嫌気性処理汚泥が形成される。曝気処理工程では、鉄化合物を含有する嫌気性処理汚泥を酸素含有気体で曝気処理し、汚泥中に存在する鉄（II）を鉄（III）に酸化させるとともに、汚泥中に溶解している炭酸ガスを除去する。本発明における曝気処理工程は、一般的な好気処理に必要とされる程度の溶存酸素量又は酸化還元電位を達成するものではなく、酸化還元電位（銀／塩化銀電極を基準とした酸化還元電位）を−１００ｍＶ以下に制御するため、好気性処理とは異なる。また、曝気処理工程では、汚泥中に存在する凝集阻害成分を生物的あるいは化学的に分解させる。凝集阻害成分としては、多糖類、タンパク質、糖タンパク質、核酸、リン脂質、フミン酸などが挙げられる。
(3) Aeration Treatment Step According to the present invention, anaerobic treatment sludge containing an iron compound is formed in the anaerobic treatment step. In the aeration treatment step, anaerobic treated sludge containing an iron compound is aerated with an oxygen-containing gas to oxidize iron (II) present in the sludge to iron (III) and carbon dioxide dissolved in the sludge. Remove the gas. The aeration treatment step in the present invention does not achieve the amount of dissolved oxygen or the redox potential required for general aerobic treatment, but the redox potential (oxidation-reduction based on the silver / silver chloride electrode). Since the potential) is controlled to -100 mV or less, it is different from the aerobic treatment. Further, in the aeration treatment step, the aggregation inhibitory component existing in the sludge is biologically or chemically decomposed. Examples of the aggregation inhibitory component include polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, and humic acid.
曝気処理により酸化された鉄（III）は、後段の凝集処理工程で凝集剤として利用できる。嫌気性処理汚泥中の鉄は、還元雰囲気下にあるので、鉄（II）として存在する。曝気処理により鉄（II）は鉄（III）に酸化される。一般的に、鉄（III）の凝集剤としての能力は、鉄（II）と比較して著しく高いため、曝気処理によって鉄（II）が鉄（III）に酸化されることにより、後段の凝集工程で必要な凝集剤の注入量を削減できる。 Iron (III) oxidized by the aeration treatment can be used as a coagulant in the coagulation treatment step in the subsequent stage. Iron in anaerobic sludge exists as iron (II) because it is in a reducing atmosphere. Iron (II) is oxidized to iron (III) by aeration treatment. In general, the ability of iron (III) as a flocculant is significantly higher than that of iron (II). Therefore, iron (II) is oxidized to iron (III) by aeration treatment to cause coagulation in the subsequent stage. The amount of coagulant injected in the process can be reduced.
また、曝気処理により汚泥中の炭酸ガスを除去し、後段の凝集工程での発泡を抑制することができる。一般的に嫌気性処理では、メタンガスとともに炭酸ガスが発生し、汚泥中に多量の炭酸ガスが溶解している。嫌気性処理汚泥に凝集剤を注入すると、溶解していた炭酸ガスが脱気され、凝集汚泥が発泡してしまい、凝集阻害や凝集槽から凝集汚泥が溢れるなどのトラブルが発生する。発泡トラブルは特に無機凝集剤を注入した際に顕著で、無機凝集剤を使用できないこともある。曝気処理により溶存炭酸ガスは脱気されるので、後段の凝集工程で発泡トラブルを回避することができる。 In addition, carbon dioxide gas in sludge can be removed by aeration treatment, and foaming in the subsequent agglutination step can be suppressed. Generally, in anaerobic treatment, carbon dioxide gas is generated together with methane gas, and a large amount of carbon dioxide gas is dissolved in sludge. When a coagulant is injected into the anaerobic treated sludge, the dissolved carbon dioxide gas is degassed and the coagulated sludge foams, causing troubles such as inhibition of coagulation and overflow of coagulated sludge from the coagulation tank. Foaming trouble is particularly remarkable when the inorganic coagulant is injected, and the inorganic coagulant may not be used in some cases. Since the dissolved carbon dioxide gas is degassed by the aeration treatment, foaming trouble can be avoided in the subsequent agglutination step.
また、曝気処理により汚泥中に存在する凝集阻害成分を生物的あるいは化学的に分解させ、後段の凝集工程で必要な凝集剤の注入量を削減することができ、さらに後段の脱水工程でケーキ含水率を低減することができる。一般的に嫌気性処理汚泥には、凝集阻害成分として、多糖類、タンパク質、糖タンパク質、核酸、リン脂質、フミン酸などの高分子物質が含まれている。これら凝集阻害成分には、嫌気性処理の最中に微生物により産生された成分や原料の有機物由来の成分などがある。また、凝集阻害成分のうち、高分子量の高分子物質が分解されることにより汚泥の粘度が低減するため、後段の凝集工程で汚泥と凝集剤の混合が容易になり、凝集剤を効率的に利用でき、凝集剤の注入量を低減することが可能となる。 In addition, the aeration treatment can biologically or chemically decompose the aggregation-inhibiting components present in the sludge, reducing the injection amount of the coagulant required in the coagulation step in the subsequent stage, and further containing water in the cake in the dehydration step in the subsequent stage. The rate can be reduced. Generally, anaerobic treated sludge contains high molecular weight substances such as polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, and humic acid as aggregation-inhibiting components. These aggregation-inhibiting components include components produced by microorganisms during anaerobic treatment and components derived from organic substances as raw materials. In addition, among the agglutination-inhibiting components, the viscosity of the sludge is reduced by decomposing the high molecular weight polymer substance, so that the sludge and the agglutinating agent can be easily mixed in the subsequent agglutination step, and the agglutinating agent can be efficiently used. It can be used and the injection amount of the flocculant can be reduced.
曝気処理工程は、１０〜５０℃の温度範囲、好ましくは２０〜４５℃、より好ましくは２５〜４０℃の温度範囲で行うことが望ましい。
曝気処理工程において、嫌気性処理汚泥のｐＨを６．５〜８．５の範囲、好ましくは７．０〜８．５、より好ましくは７．０〜８．０の範囲に調整することが望ましい。ｐＨ範囲の調整は、後段の凝集工程における凝集作用を向上させ、脱水ケーキの含水率を低下させる。
The aeration treatment step is preferably carried out in a temperature range of 10 to 50 ° C., preferably 20 to 45 ° C., more preferably 25 to 40 ° C.
In the aeration treatment step, it is desirable to adjust the pH of the anaerobic treated sludge to the range of 6.5 to 8.5, preferably 7.0 to 8.5, and more preferably 7.0 to 8.0. .. Adjusting the pH range improves the agglutination action in the subsequent agglutination step and lowers the water content of the dehydrated cake.
曝気処理工程の曝気風量は０．１〜０．５ｍ３−Ａｉｒ／（ｍ３−汚泥・ｍｉｎ）の範囲とすることが望ましく、曝気処理工程の曝気時間は３〜４８時間の範囲とすることが望ましい。曝気槽内の汚泥量（ｍ３）に対する単位時間（ｍｉｎ）当たりの空気量（ｍ３）である曝気風量が０．１ｍ３−Ａｉｒ／（ｍ３−汚泥・ｍｉｎ）未満では、汚泥粘度が高い場合には汚泥全体に曝気することが困難であり、汚泥全体を曝気処理するための時間が長時間必要となる。一方、曝気風量が０．５ｍ３−Ａｉｒ／（ｍ３−汚泥・ｍｉｎ）より大きい場合には、曝気するために大型のブロアが必要になり、また発泡のリスクが高まる。曝気風量や曝気時間が過大となると、汚泥中の凝集阻害成分だけでなく、汚泥自体の分解が進行し、後段の凝集工程や脱水工程に悪影響を及ぼす。一方、曝気風量や曝気時間が十分でない場合、曝気処理に要する時間が長くなり、巨大な曝気槽を必要とするため、経済的ではない。 The aeration air volume in the aeration treatment step should be in the range of 0.1 to 0.5 m 3- Air / (m 3 -sludge / min), and the aeration time in the aeration treatment step should be in the range of 3 to 48 hours. Is desirable. When the aeration air volume, which is the amount of air (m 3 ) per unit time (min) with respect to the sludge amount (m 3 ) in the aeration tank, is less than 0.1 m 3- Air / (m 3 -sludge / min), the sludge viscosity is high. If it is high, it is difficult to aerate the entire sludge, and it takes a long time to aerate the entire sludge. On the other hand, when the aeration air volume is larger than 0.5 m 3- Air / (m 3 -sludge / min), a large blower is required for aeration, and the risk of foaming increases. If the aeration air volume or the aeration time is excessive, not only the aggregation-inhibiting component in the sludge but also the sludge itself is decomposed, which adversely affects the subsequent aggregation process and dehydration process. On the other hand, if the aeration air volume and the aeration time are not sufficient, the time required for the aeration treatment becomes long and a huge aeration tank is required, which is not economical.
曝気処理工程の汚泥の溶存酸素濃度（ＤＯ）は１．０ｍｇ／Ｌ以下、好ましくは０．５ｍｇ／Ｌ以下、より好ましくは０．２ｍｇ／Ｌ以下とすることが望ましい。鉄（II）から鉄（III）への酸化反応は、溶存酸素濃度が１．０ｍｇ／Ｌ以下で十分進む。また、多糖類、タンパク質、糖タンパク質、核酸、リン脂質、フミン酸などの凝集阻害成分は、溶存酸素濃度が１．０ｍｇ／Ｌ以下でも生物的あるいは化学的に分解される。つまり、強い好気条件にしなくとも鉄の酸化反応や凝集阻害成分の分解は進行する。 The dissolved oxygen concentration (DO) of the sludge in the aeration treatment step is preferably 1.0 mg / L or less, preferably 0.5 mg / L or less, and more preferably 0.2 mg / L or less. The oxidation reaction from iron (II) to iron (III) proceeds sufficiently when the dissolved oxygen concentration is 1.0 mg / L or less. In addition, aggregation-inhibiting components such as polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, and humic acid are biologically or chemically decomposed even when the dissolved oxygen concentration is 1.0 mg / L or less. That is, the oxidation reaction of iron and the decomposition of the aggregation-inhibiting component proceed even if the conditions are not strongly aerobic.
曝気処理工程における嫌気性処理汚泥の酸化還元電位（銀／塩化銀電極を基準とした酸化還元電位）は、−１００ｍＶ以下、望ましくは−４００〜−１００ｍＶ、好ましくは−３５０〜−１００ｍＶ、より好ましくは−３５０〜−１５０ｍＶである。鉄（II）から鉄（III）への酸化反応は、銀／塩化銀電極を基準とした酸化還元電位が−１００ｍＶ以下で十分進む。また、多糖類、タンパク質、糖タンパク質、核酸、リン脂質、フミン酸などの凝集阻害成分は、銀／塩化銀電極を基準とした酸化還元電位が−１００ｍＶ以下であれば生物的あるいは化学的に分解される。つまり、強い酸化条件にしなくても鉄の酸化反応や凝集阻害成分の分解は進む。 The redox potential (oxidation-reduction potential based on the silver / silver chloride electrode) of the anaerobic treated sludge in the aeration treatment step is -100 mV or less, preferably -400 to -100 mV, preferably -350 to -100 mV, more preferably. Is -350 to -150 mV. The oxidation reaction from iron (II) to iron (III) proceeds sufficiently when the redox potential with respect to the silver / silver chloride electrode is -100 mV or less. In addition, aggregation-inhibiting components such as polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, and fumic acids are biologically or chemically decomposed if the oxidation-reduction potential based on the silver / silver chloride electrode is -100 mV or less. Will be done. In other words, iron oxidation reaction and decomposition of aggregation-inhibiting components proceed even if strong oxidation conditions are not used.
曝気処理工程で用いる酸素含有気体としては、酸素ガスを含む気体であれば問題なく、嫌気性処理を行う施設の内外の空気、嫌気性処理を行う施設内のごみ受入ピットやごみ選別設備などから発生する悪臭成分を含む低濃度系及び高濃度系の臭気ガス、汚水の活性汚泥処理設備から発生する曝気排ガスなどを用いることができる。脱水処理工程の後段に脱水分離液の硝化工程を含む場合には、硝化工程からの排気ガスを酸素含有気体として再利用することができる。硝化工程からの排気ガスは、通常の空気よりも酸素含有量は低いが、嫌気性処理汚泥への曝気用の気体として十分な酸素を含む。 As the oxygen-containing gas used in the aeration treatment process, there is no problem as long as it is a gas containing oxygen gas, from the air inside and outside the facility where the anaerobic treatment is performed, the waste receiving pit in the facility where the anaerobic treatment is performed, the waste sorting facility, etc. Low-concentration and high-concentration odorous gases containing malodorous components generated, aerated exhaust gas generated from activated sludge treatment equipment for sewage, and the like can be used. When the denitration separation step is included in the subsequent stage of the dehydration treatment step, the exhaust gas from the denitration step can be reused as an oxygen-containing gas. The exhaust gas from the vitrification process has a lower oxygen content than ordinary air, but contains sufficient oxygen as a gas for aeration to anaerobic treated sludge.
曝気処理工程において形成される曝気処理汚泥は、高分子物質が分解されるため、粘度が低下し、Ｂ型回転粘度計を使用し、汚泥ｐＨ７．５〜９．５、温度３５℃、ロータの回転速度６０ｍｉｎ−１の条件で測定した場合の粘度は２００ｍＰａ・ｓ以下、好ましくは１５０ｍＰａ・ｓ以下、より好ましくは１２０ｍＰａ・ｓ以下となる。 The viscosity of the aeration-treated sludge formed in the aeration-treating step decreases due to the decomposition of polymer substances, and a B-type rotational viscometer is used to use a sludge pH of 7.5 to 9.5, a temperature of 35 ° C, and a rotor. The viscosity when measured under the condition of a rotation speed of 60 min -1 is 200 mPa · s or less, preferably 150 mPa · s or less, and more preferably 120 mPa · s or less.
なお、曝気処理工程は、連続式でも回分式でもよい。
（４）凝集工程
次いで、鉄(III)を含有する曝気処理汚泥は、凝集工程において凝集剤が注入され、凝集汚泥が形成される。凝集汚泥はフロックとも呼ばれる。
The aeration treatment step may be a continuous method or a batch method.
(4) Coagulation Step Next, in the aeration-treated sludge containing iron (III), a coagulant is injected in the coagulation step to form coagulated sludge. Cohesive sludge is also called floc.
凝集剤としては、特に限定されないが、無機凝集剤、高分子凝集剤が用いられる。無機凝集剤としては、ポリ塩化アルミニウム、硫酸バンド、塩化アルミニウム、塩化第一鉄、塩化第二鉄、ポリ硫酸第一鉄、ポリ硫酸第二鉄などが挙げられる。高分子凝集剤としては、カチオン性高分子凝集剤、両性高分子凝集剤、アニオン性高分子凝集剤、ノニオン性高分子凝集剤など挙げられる。 The coagulant is not particularly limited, but an inorganic coagulant and a polymer coagulant are used. Examples of the inorganic flocculant include polyaluminum chloride, a sulfate band, aluminum chloride, ferrous chloride, ferric chloride, ferric polysulfate, ferric polysulfate and the like. Examples of the polymer flocculant include a cationic polymer flocculant, an amphoteric polymer flocculant, an anionic polymer flocculant, and a nonionic polymer flocculant.
カチオン性高分子凝集剤としては、カチオン性モノマの重合体、カチオン性モノマとノニオン性モノマとの共重合体、アミジン単位を有するアミジン系高分子凝集剤、アミジン系高分子凝集剤と上記の非アミジン系高分子凝集剤を混合した高分子凝集剤などが挙げられる。カチオン性モノマとしては、ジアルキルアミノアルキル（メタ）アクリレート、ジアルキルアミノアルキル（メタ）アクリレートの３級塩、ジアルキルアミノアルキル（メタ）アクリレートの４級塩などが挙げられ、例えば、ジメチルアミノエチル（メタ）アクリレート、ジメチルアミノエチル（メタ）アクリレートの３級塩、ジメチルアミノエチル（メタ）アクリレートの４級塩などが挙げられる。なお、アクリレート又はメタクリレートを（メタ）アクリレートと表す。また、アクリル酸又はメタクリル酸を（メタ）アクリル酸と表す。また、アクリルアミド又はメタクリルアミドを（メタ）アクリルアミドと表す。 Examples of the cationic polymer flocculant include a polymer of a cationic monoma, a copolymer of a cationic monoma and a nonionic monomer, an amidin-based polymer flocculant having an amidin unit, an amidin-based polymer flocculant, and the above-mentioned non-polymer flocculants. Examples thereof include a polymer flocculant mixed with an amidin-based polymer flocculant. Examples of the cationic monoma include dialkylaminoalkyl (meth) acrylate, tertiary salt of dialkylaminoalkyl (meth) acrylate, and quaternary salt of dialkylaminoalkyl (meth) acrylate, and examples thereof include dimethylaminoethyl (meth). Examples thereof include acrylate, a tertiary salt of dimethylaminoethyl (meth) acrylate, and a quaternary salt of dimethylaminoethyl (meth) acrylate. In addition, acrylate or methacrylate is represented as (meth) acrylate. Further, acrylic acid or methacrylic acid is referred to as (meth) acrylic acid. Further, acrylamide or methacrylamide is referred to as (meth) acrylamide.
アニオン性高分子凝集剤としては、アニオン性モノマの重合体、アニオン性モノマとノニオン性モノマとの共重合体などが挙げられる。アニオン性モノマとしては、（メタ）アクリル酸、（メタ）アクリル酸ナトリウムなどが挙げられる。ノニオン性モノマとしては、（メタ）アクリルアミド、Ｎ，Ｎ−ジメチル（メタ）アクリルアミドなどが挙げられる。 Examples of the anionic polymer flocculant include a polymer of anionic monoma, a copolymer of anionic monoma and nonionic monoma, and the like. Examples of the anionic monoma include (meth) acrylic acid and sodium (meth) acrylic acid. Examples of nonionic monomas include (meth) acrylamide, N, N-dimethyl (meth) acrylamide and the like.
両性高分子凝集剤としては、上述のカチオン性モノマとアニオン性モノマとの共重合体、カチオン性モノマとアニオン性モノマとノニオン性モノマとの共重合体などが挙げられる。 Examples of the amphoteric polymer flocculant include the above-mentioned copolymers of cationic monomas and anionic monomas, and copolymers of cationic monomas, anionic monomas and nonionic monomas.
高分子凝集剤の注入率は、汚泥のＴＳ濃度に対して１〜７質量％がよく、好ましくは２〜５質量％であるが、従来の嫌気性処理汚泥の凝集方法における注入量と比較して１０〜３０％の削減を達成できる。ここで、ＴＳとは全蒸発残留物のことである。ＴＳの分析方法は下水道試験法に準拠した。フロックは、直径、すなわちフロック径が数ミリ程度であり、沈降分離性が高いことが好ましい。 The injection rate of the polymer flocculant is preferably 1 to 7% by mass, preferably 2 to 5% by mass, based on the TS concentration of the sludge, but is compared with the injection amount in the conventional method of coagulating anaerobic treated sludge. A 10-30% reduction can be achieved. Here, TS is a total evaporation residue. The TS analysis method was based on the sewerage test method. It is preferable that the flocs have a diameter, that is, a flocs diameter of about several millimeters, and have high sedimentation separability.
凝集の前に、曝気処理汚泥を希釈してもよく、凝集剤注入率をさらに低減することができる。希釈液としては、凝集反応に影響を与えない性状であればよく、例えば、溶解性成分濃度が低い水が好ましい。例えば、水道水、飲料水、工業用水、生物処理水、生物処理水のろ過水、生物脱臭装置廃液の生物処理水などが挙げられる。希釈することによって、曝気処理汚泥の粘度が低下するとともに溶存塩類濃度が低下し、凝集剤の分散性がさらに向上する。希釈された曝気処理汚泥のＭ−アルカリ度は、４０００ｍｇ／Ｌ以下が好ましく、２５００ｍｇ／Ｌ以下がさらに好ましい。希釈された消化汚泥の電気伝導度は１２００ｍＳ／ｍ以下に調整することが好ましく、７５０ｍＳ／ｍ以下に調整することがさらに好ましい。 The aerated sludge may be diluted prior to agglomeration, further reducing the coagulant injection rate. The diluting solution may have properties that do not affect the agglutination reaction, and for example, water having a low concentration of soluble components is preferable. For example, tap water, drinking water, industrial water, biologically treated water, filtered water of biologically treated water, biologically treated water of biological deodorizing device waste liquid, and the like can be mentioned. By diluting, the viscosity of the aerated sludge is lowered, the concentration of dissolved salts is lowered, and the dispersibility of the flocculant is further improved. The M-alkalinity of the diluted aeration-treated sludge is preferably 4000 mg / L or less, and more preferably 2500 mg / L or less. The electrical conductivity of the diluted digestive sludge is preferably adjusted to 1200 mS / m or less, and more preferably 750 mS / m or less.
（５）脱水工程
脱水工程では、凝集汚泥を脱水ケーキと脱水分離液とに固液分離する。脱水前に濃縮処理して得た濃縮汚泥を脱水ケーキと脱水分離液とに固液分離してもよい。本発明の処理方法により得られる脱水ケーキの含水率は８５％以下と低含水率であるため、コンポスト、炭、燃料などの再資源化が可能である。
(5) Dewatering step In the dewatering step, the coagulated sludge is solid-liquid separated into a dewatered cake and a dewatering separation solution. The concentrated sludge obtained by the concentration treatment before dehydration may be solid-liquid separated into a dehydrated cake and a dehydrated separation liquid. Since the water content of the dehydrated cake obtained by the treatment method of the present invention is as low as 85% or less, compost, charcoal, fuel and the like can be recycled.
（６）濃縮工程
凝集により形成された凝集汚泥を固液分離により濃縮してから脱水してもよい。濃縮により濃縮汚泥と濃縮分離液とに固液分離される。ＴＳ濃度が５〜１５質量％に濃縮された汚泥は、脱水工程においてより効率的に脱水することができる。
(6) Concentration step The agglomerated sludge formed by agglomeration may be concentrated by solid-liquid separation and then dehydrated. By concentration, it is solid-liquid separated into concentrated sludge and concentrated separation liquid. Sludge with a TS concentration of 5 to 15% by mass can be dehydrated more efficiently in the dehydration step.
次に、本発明の有機物の処理方法を実施する装置について説明する。
本発明の有機物の処理装置は、有機物に鉄化合物を注入する鉄化合物注入手段と、
鉄化合物を注入する配管を有し、鉄（II）の共存下で有機物を嫌気性処理し、嫌気性処理汚泥を形成させる嫌気性処理槽と、
酸化還元電位測定装置を有し、当該嫌気性処理汚泥に酸素含有気体を接触させ、鉄（II）を鉄（III）に酸化させて、鉄（III）を含む曝気処理汚泥を形成させる曝気槽と、
当該曝気処理汚泥に凝集剤を注入し、凝集汚泥を形成させる凝集槽と、
当該凝集汚泥を脱水する脱水装置と、
当該脱水装置からの脱水分離液に含まれるアンモニアを硝化する硝化槽と、
当該硝化槽からの排気ガスを当該曝気槽に添加する酸素含有気体供給配管と、
を具備する。
Next, an apparatus for carrying out the method for treating an organic substance of the present invention will be described.
The organic substance processing apparatus of the present invention includes an iron compound injection means for injecting an iron compound into an organic substance and an iron compound injection means.
An anaerobic treatment tank that has a pipe for injecting iron compounds, anaerobicly treats organic substances in the coexistence of iron (II), and forms anaerobic treated sludge.
An aeration tank having an oxidation-reduction potential measuring device, in which an oxygen-containing gas is brought into contact with the anaerobic treated sludge to oxidize iron (II) to iron (III) to form an aerated treated sludge containing iron (III). When,
A coagulation tank that injects a coagulant into the aeration-treated sludge to form coagulation sludge,
A dehydrator that dehydrates the aggregated sludge,
A nitrification tank that nitrifies the ammonia contained in the dehydration separation solution from the dehydrator,
An oxygen-containing gas supply pipe that adds exhaust gas from the nitrification tank to the aeration tank, and
To be equipped.
有機物に鉄化合物を注入する鉄化合物注入手段は、有機物貯槽、可溶化槽、可溶化物貯槽、有機物又は可溶化槽で処理された可溶化物を各槽に搬送する配管、又は嫌気性処理槽の少なくとも１に設けることができる。 The iron compound injection means for injecting an iron compound into an organic substance is an organic substance storage tank, a solubilization tank, a solubilized product storage tank, a pipe for transporting the organic substance or the solubilized material treated in the solubilized material to each tank, or an anaerobic treatment tank. It can be provided in at least one of.
曝気槽と凝集槽には曝気槽内の汚泥の粘度に応じて酸素含有気体の曝気風量を調整する制御装置が電気的に連結されていてもよく、曝気槽内の汚泥の粘度を計測する粘度計を設置することが好ましい。 A control device that adjusts the aeration air volume of the oxygen-containing gas according to the viscosity of the sludge in the aeration tank may be electrically connected to the aeration tank and the coagulation tank, and the viscosity for measuring the viscosity of the sludge in the aeration tank. It is preferable to install a meter.
以下、各槽について説明する。
（Ａ）可溶化槽
鉄化合物を注入する手段を具備する以外は、有機物を可溶化処理するために一般に用いられる可溶化槽を制限なく用いることができる。
Hereinafter, each tank will be described.
(A) Solubilization tank A solubilization tank generally used for solubilizing organic substances can be used without limitation, except that a means for injecting an iron compound is provided.
（Ｂ）可溶化物貯槽
鉄化合物を注入する手段を具備する以外は、有機物を可溶化処理した後の可溶化物を嫌気性処理するまでの間、貯蔵するために一般に用いられる可溶化物貯槽を制限なく用いることができる。
(B) Soluble storage tank A solubilized storage tank generally used for storing solubilized substances after solubilizing organic substances until anaerobic treatment, except that the solubilized product is provided with a means for injecting an iron compound. Can be used without limitation.
（Ｃ）配管
鉄化合物を注入する手段を具備する以外は、有機物又は可溶化物を各槽に搬送するために一般に用いられる配管を制限なく用いることができる。
(C) Piping Except for providing a means for injecting an iron compound, a piping generally used for transporting an organic substance or a solubilized substance to each tank can be used without limitation.
（Ｄ）嫌気性処理槽
廃棄物系バイオマス処理設備や下水処理施設などで一般に用いられる完全混合型嫌気性処理槽や乾式メタン発酵槽など、公知の嫌気性処理槽を制限なく用いることができる。
(D) Anaerobic treatment tanks Known anaerobic treatment tanks such as fully mixed anaerobic treatment tanks and dry methane fermentation tanks generally used in waste biomass treatment facilities and sewage treatment facilities can be used without limitation.
（Ｅ）曝気槽
水処理施設などで一般に用いられる曝気槽を制限なく用いることができる。曝気槽には、嫌気性処理汚泥を供給する手段、酸素含有気体を曝気槽に供給するための曝気手段、曝気処理汚泥の引き抜き手段を備える。曝気手段としては、散気式、機械撹拌式、散気式と機械撹拌式の併用式などが挙げられる。散気式の曝気装置は、散気装置とブロアから構成される。散気装置としては、散気板、散気管、多孔管、スパージャなどが挙げられる。曝気手段は、曝気槽底部から曝気槽内の汚泥に気泡を供給できるように設けることが好ましい。また、曝気槽には、運転管理する計測機器としてｐＨ計、ＤＯ計、ＯＲＰ計、粘度計を備えることが好ましい。また、曝気槽の汚泥のｐＨを制御するため、酸注入手段やアルカリ注入手段を備えることが好ましい。
(E) Aeration tank An aeration tank generally used in a water treatment facility or the like can be used without limitation. The aeration tank is provided with a means for supplying anaerobic treated sludge, an aeration means for supplying an oxygen-containing gas to the aeration tank, and a means for extracting the aeration-treated sludge. Examples of the aeration means include an aeration type, a mechanical agitation type, and a combined type of an aeration type and a mechanical agitation type. The aeration type aeration device consists of an aeration device and a blower. Examples of the air diffuser include an air diffuser, an air diffuser, a perforated pipe, and a sparger. The aeration means is preferably provided so that air bubbles can be supplied from the bottom of the aeration tank to the sludge in the aeration tank. Further, it is preferable that the aeration tank is provided with a pH meter, a DO meter, an ORP meter, and a viscometer as measuring devices for operation management. Further, in order to control the pH of sludge in the aeration tank, it is preferable to provide an acid injection means or an alkali injection means.
（Ｆ）凝集槽
水処理施設などで一般に用いられる凝集槽を制限なく用いることができ、曝気処理した曝気処理汚泥を供給する手段、凝集剤を注入する手段、曝気処理汚泥と凝集剤を混合する手段、凝集汚泥の引き抜き手段を備える。
(F) Coagulation tank A coagulation tank generally used in water treatment facilities can be used without limitation, and a means for supplying aerated treated sludge, a means for injecting a coagulant, and a means for mixing aerated sludge and a coagulant. Means and means for extracting coagulated sludge are provided.
また、２つ以上の凝集槽を設けて、凝集剤を分割注入してもよい。例えば、凝集槽を２つ以上設ける場合、第１の凝集槽では無機凝集剤を注入し、第２以降の凝集槽では高分子凝集剤を注入し、凝集汚泥を形成してもよいし、第１の凝集槽でも高分子凝集剤を注入し、第２以降の凝集槽でも高分子凝集剤を注入してもよい。また、凝集槽を３つ以上設ける場合、第１の凝集槽に無機凝集剤を分割注入し、第２の凝集槽及び第３以降の凝集槽に高分子凝集剤を分割注入してもよい。凝集剤の注入量及び注入回数は、処理すべき汚泥の性状及び凝集槽の数に応じて適宜設定することができる。 Further, two or more coagulation tanks may be provided to separately inject the coagulant. For example, when two or more coagulation tanks are provided, an inorganic coagulant may be injected into the first coagulation tank, and a polymer coagulant may be injected into the second and subsequent coagulation tanks to form a coagulation sludge. The polymer coagulant may be injected in the coagulation tank 1 and the polymer coagulant may be injected in the second and subsequent coagulation tanks. When three or more coagulation tanks are provided, the inorganic coagulant may be dividedly injected into the first coagulation tank, and the polymer coagulant may be dividedly injected into the second coagulation tank and the third and subsequent coagulation tanks. The injection amount and the number of injections of the coagulant can be appropriately set according to the properties of the sludge to be treated and the number of coagulation tanks.
また、凝集槽は脱水装置に設けられていてもよい。このような脱水装置としては、一部の遠心脱水機が挙げられ、このような遠心脱水機は、内部に凝集槽に相当する領域を備えており、遠心力により汚泥と凝集剤を混合し、凝集汚泥を形成する。 Further, the coagulation tank may be provided in the dehydrator. Examples of such a dehydrator include some centrifugal dehydrators, and such a centrifugal dehydrator is provided with an area corresponding to a coagulation tank inside, and sludge and a coagulant are mixed by centrifugal force. Form coagulated sludge.
（Ｇ）脱水装置
凝集槽で調整された凝集汚泥又は濃縮機で濃縮された濃縮汚泥を脱水する脱水装置を備える。脱水装置としては特に限定されず、凝集汚泥又は濃縮汚泥へ圧力を付与する手段と、固形物と脱水分離液とに分離する手段を具備することが好ましい。脱水装置としては、ベルトプレス、スクリュープレス、遠心脱水機、フィルタープレス、多重円板型脱水機、多重円盤型スクリュープレス、ロータリープレスなどが挙げられる。
(G) Dehydrating device A dehydrating device for dehydrating the coagulated sludge prepared in the coagulation tank or the concentrated sludge concentrated by the concentrator is provided. The dehydration device is not particularly limited, and it is preferable to provide a means for applying pressure to the aggregated sludge or concentrated sludge and a means for separating the solid matter and the dehydration separation liquid. Examples of the dehydrator include a belt press, a screw press, a centrifugal dehydrator, a filter press, a multiple disk type dehydrator, a multiple disk type screw press, and a rotary press.
（Ｈ）硝化槽
脱水装置からの脱水分離液に含まれるアンモニアを硝化する硝化槽は、硝化槽からの排気ガスを曝気装置に送る酸素含有気体供給管を具備する点を除いて、水処理施設などで一般に用いられる硝化槽を制限なく用いることができる。
(H) Nitrification tank The nitrification tank that nitrifies the ammonia contained in the dehydration separation liquid from the dehydrator is a water treatment facility except that it is equipped with an oxygen-containing gas supply pipe that sends the exhaust gas from the nitrification tank to the aeration device. The nitrification tank generally used in the above can be used without limitation.
（Ｉ）粘度計
曝気槽と凝集槽には曝気槽内の汚泥の粘度に応じて酸素含有気体の曝気風量を調整する制御装置が電気的に連結されていてもよい。通常、曝気槽内の汚泥の粘度の計測は、試料を採取して粘度計で計測するため、自動連続計測を行うことができない。本発明では、凝集槽の撹拌機の撹拌速度に基づいて、凝集槽内の嫌気性処理汚泥の粘度を推測し、曝気処理中の嫌気性処理汚泥の粘度を推測して、曝気風量を調整してもよい。具体的には、たとえば、凝集槽の撹拌装置に電流検出部を設け、検出された電流から撹拌速度、すなわち撹拌抵抗を求め、曝気槽内の嫌気性処理汚泥の粘度変動を推定して、所定の曝気風量に調整する。
(I) Viscometer A control device that adjusts the aeration air volume of the oxygen-containing gas according to the viscosity of the sludge in the aeration tank may be electrically connected to the aeration tank and the aeration tank. Normally, the viscosity of sludge in an aeration tank is measured by collecting a sample and measuring it with a viscometer, so that automatic continuous measurement cannot be performed. In the present invention, the viscosity of the anaerobic treated sludge in the coagulation tank is estimated based on the stirring speed of the stirrer in the coagulation tank, the viscosity of the anaerobic treated sludge during the aeration treatment is estimated, and the aeration air volume is adjusted. You may. Specifically, for example, a current detection unit is provided in the stirring device of the coagulation tank, the stirring speed, that is, the stirring resistance is obtained from the detected current, and the viscosity fluctuation of the anaerobic treated sludge in the aeration tank is estimated and determined. Adjust to the aeration air volume of.
（Ｊ）濃縮装置
凝集槽で形成された凝集汚泥を固液分離して濃縮汚泥を形成する固液分離装置を備えていてもよい。固液分離装置としては、特に限定されず、重力濃縮法が適用される単なる槽、遠心濃縮法が適用される遠心分離機、浮上濃縮法が適用される分離機、スクリーンを用いた分離機等が挙げられる。中でも、濃縮分離液を通過させる多数のスリットを形成したスクリーンと、スリットに配置され、スリットの目詰まりを除去するとともに、濃縮汚泥を濃縮機の流入側から排出側に搬送する多数の楕円板とを備える楕円板型濃縮機が好ましい。楕円板型濃縮機は、例えば、スクリーンで受け止められた凝集汚泥は、出口方向に回転する多数の楕円板によってスクリーン上を搬送され、この過程でスリットと楕円板との隙間から濃縮分離液が落下してろ過され、凝集汚泥中の固体成分は分離捕集される。さらに、スクリーン上の凝集汚泥を圧搾する加圧板がスクリーン上部に配置された機械構造も好ましく用いることができる。
(J) Concentrating device A solid-liquid separating device that solid-liquid separates coagulated sludge formed in a coagulation tank to form concentrated sludge may be provided. The solid-liquid separator is not particularly limited, and is a simple tank to which the gravity concentration method is applied, a centrifuge to which the centrifugal concentration method is applied, a separator to which the levitation concentration method is applied, a separator using a screen, etc. Can be mentioned. Among them, a screen having a large number of slits through which the concentrated separation liquid passes, and a large number of elliptical plates arranged in the slits to remove clogging of the slits and to transport the concentrated sludge from the inflow side to the discharge side of the concentrator. An elliptical plate type concentrator provided with is preferable. In the elliptical plate type concentrator, for example, the coagulated sludge received by the screen is conveyed on the screen by a large number of elliptical plates rotating in the outlet direction, and in this process, the concentrated separation liquid drops from the gap between the slit and the elliptical plate. The solid component in the coagulated sludge is separated and collected. Further, a mechanical structure in which a pressure plate for squeezing agglomerated sludge on the screen is arranged on the upper part of the screen can also be preferably used.
次に、実施例及び比較例により、本発明を具体的に説明する。
［実施例１］
鉄化合物の注入により、嫌気性処理が効率化されることを確認するために、鉄化合物を異なる濃度で注入し、有機物の嫌気性処理を行った。処理原料の有機物として、種々の食品製造廃棄物の混合物を使用した。鉄化合物として、ポリ硫酸第二鉄を使用した。試験方法は以下の通りである。
Next, the present invention will be specifically described with reference to Examples and Comparative Examples.
[Example 1]
In order to confirm that the injection of the iron compound makes the anaerobic treatment more efficient, the iron compound was injected at different concentrations to perform the anaerobic treatment of the organic matter. As the organic matter of the processing raw material, a mixture of various food production wastes was used. Ferric polysulfate was used as the iron compound. The test method is as follows.
実際に稼働しているメタン発酵処理施設（施設Ｆ１）にて、８００ｍ３の嫌気性処理槽にＨＲＴ３０日で原料を投入し、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が下記表１に示す濃度となるように鉄化合物を注入し、温度３５℃で嫌気性処理し、ガス発生量と有機酸濃度を測定した。ガス発生量の測定は膜式ガスメーターを用いて行った。有機酸濃度の測定は、高速液体クロマトグラフィー（検出器：ＲＩ、分離カラム：Shodex RSpak KC-811、カラム温度６０℃、移動相：０．１％リン酸水溶液）を用いて行った。 At the methane fermentation treatment facility (facility F1) that is actually in operation , the raw materials are put into an 800 m 3 anaerobic treatment tank in 30 days at HRT, and the iron concentration in the anaerobic treatment sludge after injection of the iron compound is shown in Table 1 below. The iron compound was injected so as to have the concentration shown in (1), and anaerobic treatment was performed at a temperature of 35 ° C., and the amount of gas generated and the concentration of organic acid were measured. The amount of gas generated was measured using a membrane gas meter. The organic acid concentration was measured by high performance liquid chromatography (detector: RI, separation column: Shodex RSpak KC-811, column temperature 60 ° C., mobile phase: 0.1% aqueous phosphoric acid solution).
表１に試験結果を示す。これらの試験結果から、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が鉄換算で１００ｍｇ／Ｌ以上であれば、ガス発生量が大きく、有機酸の蓄積が少なく、嫌気性処理が効率化、安定化できることが確認できた。 Table 1 shows the test results. From these test results, if the iron concentration in the anaerobic treatment sludge after injection of the iron compound is 100 mg / L or more in terms of iron, the amount of gas generated is large, the accumulation of organic acids is small, and the anaerobic treatment is efficient. , It was confirmed that it can be stabilized.
［実施例２］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、嫌気性処理が効率化されること、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。
[Example 2]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. In order to confirm that the anaerobic treatment is efficient, the aggregation is efficient, and the dehydration is efficient by forming the aggregated sludge and finally dehydrating the aggregated sludge, the following tests are performed. went.
実施例１と同じメタン発酵処理施設（施設Ｆ１）にて、種々の食品製造廃棄物の混合物を原料とし、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が６３ｍｇ／Ｌ（鉄換算）もしくは２９７ｍｇ／Ｌ（鉄換算）になるように鉄化合物を注入し、嫌気性処理を行った。次に、２０Ｌの曝気処理槽に１０Ｌの嫌気性処理汚泥を投入し、温度３５℃、曝気風量０．３ｍ３‐Ａｉｒ／（ｍ３‐汚泥・ｍｉｎ）で、２４時間、曝気処理した。次に、サンプリングした曝気処理汚泥をアミジン系高分子凝集剤で凝集させ、ベルトプレス脱水機で脱水した。表２に試験結果を示す。 At the same methane fermentation treatment facility (facility F1) as in Example 1, the iron concentration in the anaerobic treated sludge after injection of iron compounds is 63 mg / L (iron equivalent) or higher, using a mixture of various food production wastes as a raw material. An iron compound was injected so as to be 297 mg / L (iron equivalent), and anaerobic treatment was performed. Next, 10 L of anaerobic treated sludge was put into a 20 L aeration treatment tank, and aeration treatment was performed at a temperature of 35 ° C. and an aeration air volume of 0.3 m 3- Air / (m 3- sludge / min) for 24 hours. Next, the sampled aeration-treated sludge was agglomerated with an amidine-based polymer flocculant and dehydrated with a belt press dehydrator. Table 2 shows the test results.
これらの試験結果から、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が１００ｍｇ／Ｌ（鉄換算）以上になるように鉄化合物を注入することによって、嫌気性処理を効率化できるとともに、ケーキ含水率を低減できることが確認できた。曝気処理槽内の汚泥のＤＯは、０．０〜０．２ｍｇ／Ｌ、ＯＲＰ（銀／塩化銀電極を基準としたＯＲＰ）は−２４０〜−３５０ｍＶであった。 Based on these test results, anaerobic treatment after injection of the iron compound By injecting the iron compound so that the iron concentration in the sludge is 100 mg / L (iron equivalent) or more, the anaerobic treatment can be made more efficient and the cake can be treated. It was confirmed that the water content could be reduced. The DO of the sludge in the aeration treatment tank was 0.0 to 0.2 mg / L, and the ORP (ORP based on the silver / silver chloride electrode) was -240 to -350 mV.
［実施例３］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、嫌気性処理が効率化されること、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。
[Example 3]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. In order to confirm that the anaerobic treatment is efficient, the aggregation is efficient, and the dehydration is efficient by forming the aggregated sludge and finally dehydrating the aggregated sludge, the following tests are performed. went.
実施例１及び２とは異なるメタン発酵処理施設（施設Ｆ２）にて、１０００ｍ３の嫌気性処理槽にＨＲＴ３０日で原料を投入し、温度３５℃で嫌気性処理した。種々の食品製造廃棄物の混合物を可溶化処理した可溶化物を原料とし、可溶化物貯槽に鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が５０ｍｇ／Ｌ（鉄換算）もしくは２００ｍｇ／Ｌ（鉄換算）になるように鉄化合物を注入し、嫌気性処理を行った。鉄化合物として、ポリ硫酸第二鉄を使用した。
At a methane fermentation treatment facility (facility F2) different from Examples 1 and 2 , the raw materials were put into an anaerobic treatment tank of 1000 m 3 at
次に、２０Ｌの曝気処理槽に１０Ｌの嫌気性処理汚泥を投入し、温度３５℃、曝気風量０．３ｍ３‐Ａｉｒ／（ｍ３‐汚泥・ｍｉｎ）で、２４時間、曝気処理した。次に、サンプリングした曝気処理汚泥をアミジン系高分子凝集剤で凝集させ、ベルトプレス脱水機で脱水した。表３に試験結果を示す。 Next, 10 L of anaerobic treated sludge was put into a 20 L aeration treatment tank, and aeration treatment was performed at a temperature of 35 ° C. and an aeration air volume of 0.3 m 3- Air / (m 3- sludge / min) for 24 hours. Next, the sampled aeration-treated sludge was agglomerated with an amidine-based polymer flocculant and dehydrated with a belt press dehydrator. Table 3 shows the test results.
これらの試験結果から、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が１００ｍｇ／Ｌ（鉄換算）以上になるように鉄化合物を注入することによって、嫌気性処理を効率化できるとともに、ケーキ含水率を低減できることが確認できた。曝気処理槽内の汚泥のＤＯは、０．０〜０．２ｍｇ／Ｌ、ＯＲＰ（銀／塩化銀電極を基準としたＯＲＰ）は−２１０〜−３３０ｍＶであった。 Based on these test results, anaerobic treatment after injection of the iron compound By injecting the iron compound so that the iron concentration in the sludge is 100 mg / L (iron equivalent) or more, the anaerobic treatment can be made more efficient and the cake can be treated. It was confirmed that the water content could be reduced. The DO of the sludge in the aeration treatment tank was 0.0 to 0.2 mg / L, and the ORP (ORP based on the silver / silver chloride electrode) was -10 to -330 mV.
［実施例４］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。試験方法は以下の通りである。
[Example 4]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. The following tests were conducted in order to confirm that the coagulation is efficient and the dehydration is efficient by forming the coagulated sludge and finally dehydrating the coagulated sludge. The test method is as follows.
実施例３と同じメタン発酵処理施設（施設Ｆ２）にて、種々の食品製造廃棄物の混合物を可溶化処理した可溶化物を原料とし、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が２００ｍｇ／Ｌ（鉄換算）になるように可溶化貯槽に鉄化合物を注入し、嫌気性処理を行った。鉄化合物として、ポリ硫酸第二鉄を使用した。 At the same methane fermentation treatment facility (facility F2) as in Example 3, a solubilized product obtained by solubilizing a mixture of various food production wastes was used as a raw material, and the iron concentration in the anaerobic treated sludge after injection of the iron compound was increased. An iron compound was injected into the solubilized storage tank so as to be 200 mg / L (iron equivalent), and anaerobic treatment was performed. Ferric polysulfate was used as the iron compound.
次に、２０Ｌの曝気処理槽に１０Ｌの嫌気性処理汚泥を投入し、温度３５℃、曝気風量０．３ｍ３‐Ａｉｒ／（ｍ３‐汚泥・ｍｉｎ）で曝気処理した。曝気処理汚泥は所定の曝気時間経過後にサンプリングした。次に、サンプリングした曝気処理汚泥にアミジン系高分子凝集剤を注入して凝集させた後、ベルトプレスで脱水した。表４に試験結果を示す。 Next, 10 L of anaerobic treated sludge was put into a 20 L aeration treatment tank, and aeration treatment was performed at a temperature of 35 ° C. and an aeration air volume of 0.3 m 3- Air / (m 3- sludge / min). The aeration-treated sludge was sampled after a predetermined aeration time. Next, an amidine-based polymer flocculant was injected into the sampled aeration-treated sludge to coagulate it, and then dehydrated by a belt press. Table 4 shows the test results.
これらの試験結果から、曝気処理をしない嫌気性処理汚泥（曝気時間０ｈ）に対して、曝気処理汚泥は、ケーキ含水率を低減できること、凝集剤注入率を低減できること、及び曝気処理汚泥の凝集時の発泡現象が起こらなかったことが確認できる。曝気時間が３〜４８時間でケーキ含水率を低減でき、最終的にはケーキ含水率を８２％以下まで低減できた。曝気処理を行わない嫌気性処理汚泥は黒色であったが、３時間以上の曝気時間で嫌気性処理汚泥は褐色に変化し、曝気処理により鉄（II）が鉄（III）に酸化されたことを確認した。曝気処理槽内の汚泥のＤＯは、０．０〜０．２ｍｇ／Ｌ、銀／塩化銀電極を基準とした酸化還元電位（ＯＲＰ）は−１７０〜−３２０ｍＶであった。 From these test results, the aeration-treated sludge can reduce the moisture content of the cake, the coagulant injection rate, and the aeration-treated sludge when the aeration-treated sludge is agglomerated. It can be confirmed that the foaming phenomenon did not occur. The cake moisture content could be reduced by aeration time of 3 to 48 hours, and finally the cake moisture content could be reduced to 82% or less. The anaerobic treated sludge without aeration treatment was black, but the anaerobic treated sludge turned brown after an aeration time of 3 hours or more, and iron (II) was oxidized to iron (III) by the aeration treatment. It was confirmed. The DO of the sludge in the aeration treatment tank was 0.0 to 0.2 mg / L, and the redox potential (ORP) based on the silver / silver chloride electrode was -170 to -320 mV.
［実施例５］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。実施例４とは、曝気風量を変更した。試験方法は以下の通りである。
[Example 5]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. The following tests were conducted in order to confirm that the coagulation is efficient and the dehydration is efficient by forming the coagulated sludge and finally dehydrating the coagulated sludge. The aeration air volume was changed from that of Example 4. The test method is as follows.
実施例３及び４と同じメタン発酵処理施設（施設Ｆ２）にて、種々の食品製造廃棄物の混合物を可溶化処理した可溶化物を原料とし、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が２００ｍｇ／Ｌ（鉄換算）になるように可溶化物貯槽に鉄化合物を注入し、嫌気性処理を行った。次に、２０Ｌの曝気処理槽に１０Ｌの嫌気性処理汚泥を投入し、温度３５℃、曝気風量０．１ｍ３‐Ａｉｒ／（ｍ３‐汚泥・ｍｉｎ）で曝気処理した。曝気処理汚泥は所定の曝気時間経過後にサンプリングした。次に、サンプリングした曝気処理汚泥にアミジン系高分子凝集剤を注入して凝集させ、ベルトプレス脱水機で脱水した。表５に試験結果を示す。 At the same methane fermentation treatment facility (facility F2) as in Examples 3 and 4, iron in anaerobic treated sludge after injection of an iron compound is used as a raw material, which is a solubilized product obtained by solubilizing a mixture of various food production wastes. An iron compound was injected into a solubilized product storage tank so that the concentration became 200 mg / L (iron equivalent), and anaerobic treatment was performed. Next, 10 L of anaerobic treated sludge was put into a 20 L aeration treatment tank, and aeration treatment was performed at a temperature of 35 ° C. and an aeration air volume of 0.1 m 3- Air / (m 3- sludge / min). The aeration-treated sludge was sampled after a predetermined aeration time. Next, an amidine-based polymer flocculant was injected into the sampled aeration-treated sludge to coagulate it, and dehydrated with a belt press dehydrator. Table 5 shows the test results.
これらの試験結果から、曝気処理をしない嫌気性処理汚泥（０ｈ）に対して、曝気処理汚泥は、ケーキ含水率を低減できること、凝集剤注入率を低減できること、及び曝気処理汚泥の凝集時の発泡現象が起こらなかったことが確認できる。曝気時間が３〜４８時間でケーキ含水率を低減でき、最終的にはケーキ含水率を８２％以下まで低減できた。曝気処理を行わない嫌気性処理汚泥は黒色であったが、３時間以上の曝気時間で嫌気性処理汚泥は褐色に変化し、曝気処理により鉄（II）が鉄（III）に酸化されたことを確認した。曝気処理槽内の汚泥のＤＯは、０．０〜０．１ｍｇ／Ｌ、ＯＲＰ（銀／塩化銀電極を基準としたＯＲＰ）は−２４０〜−３１０ｍＶであった。 From these test results, the aerated sludge can reduce the moisture content of the cake, the coagulant injection rate, and the foaming of the aerated sludge when it is agglomerated, as opposed to the anaerobic sludge (0h) which is not aerated. It can be confirmed that the phenomenon did not occur. The cake moisture content could be reduced by aeration time of 3 to 48 hours, and finally the cake moisture content could be reduced to 82% or less. The anaerobic treated sludge without aeration treatment was black, but the anaerobic treated sludge turned brown after an aeration time of 3 hours or more, and iron (II) was oxidized to iron (III) by the aeration treatment. It was confirmed. The DO of the sludge in the aeration treatment tank was 0.0 to 0.1 mg / L, and the ORP (ORP based on the silver / silver chloride electrode) was -240 to -310 mV.
実施例４及び５の結果を図１０に示す。図１０から、同じ凝集剤注入率であっても、曝気風量が多いほど、脱水ケーキの含水率が低下していることがわかる。
［実施例６］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。実施例３〜５では曝気処理は回分式で実施したが、実施例６では曝気処理を連続式で実施した。試験方法は以下の通りである。
The results of Examples 4 and 5 are shown in FIG. From FIG. 10, it can be seen that the water content of the dehydrated cake decreases as the aeration air volume increases, even if the coagulant injection rate is the same.
[Example 6]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. The following tests were conducted in order to confirm that the coagulation is efficient and the dehydration is efficient by forming the coagulated sludge and finally dehydrating the coagulated sludge. In Examples 3 to 5, the aeration treatment was carried out in a batch manner, but in Example 6, the aeration treatment was carried out in a continuous manner. The test method is as follows.
実施例３〜５と同じメタン発酵処理施設（施設Ｆ２）にて、種々の食品製造廃棄物の混合物を可溶化処理した可溶化物を原料とし、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が２００ｍｇ／Ｌ（鉄換算）になるように可溶化貯槽に鉄化合物を注入し、嫌気性処理を行った。鉄化合物としてポリ硫酸第二鉄を使用した。 At the same methane fermentation treatment facility (facility F2) as in Examples 3 to 5, iron in anaerobic treated sludge after injection of an iron compound is used as a raw material, which is a solubilized product obtained by solubilizing a mixture of various food production wastes. An iron compound was injected into the solubilized storage tank so that the concentration became 200 mg / L (iron equivalent), and anaerobic treatment was performed. Ferric polysulfate was used as the iron compound.
次に、６０ｍ３の曝気処理槽に嫌気性処理汚泥を４ｍ３／ｈで供給し、曝気処理汚泥を４ｍ３／ｈで曝気処理槽から引き抜き、凝集槽に供給した。曝気風量は０．３ｍ３‐Ａｉｒ／（ｍ３‐汚泥・ｍｉｎ）とした。曝気処理槽内の汚泥に硫酸を注入し、汚泥のｐＨを８．０〜８．２に制御した。凝集槽では、曝気処理汚泥とアミジン系高分子凝集剤を混合し、凝集汚泥を形成した。凝集汚泥はスクリュープレス脱水機で脱水した。 Next, the anaerobic treated sludge was supplied to the 60 m 3 aeration treatment tank at 4 m 3 / h, and the aeration treated sludge was withdrawn from the aeration treatment tank at 4 m 3 / h and supplied to the coagulation tank. The aeration air volume was 0.3 m 3- Air / (m 3 -sludge / min). Sulfuric acid was injected into the sludge in the aeration treatment tank to control the pH of the sludge to 8.0 to 8.2. In the coagulation tank, aeration-treated sludge and an amidine-based polymer coagulant were mixed to form coagulated sludge. The coagulated sludge was dehydrated with a screw press dehydrator.
比較例として、曝気処理をしない嫌気性処理汚泥も同様な方法で凝集、脱水を行った。表６に試験結果を示す。 As a comparative example, anaerobic treated sludge that was not aerated was also aggregated and dehydrated in the same manner. Table 6 shows the test results.
これらの試験結果から、曝気処理をしない嫌気性処理汚泥に対して、曝気処理汚泥では、ケーキ含水率を低減できること、凝集剤注入率を低減できること、及び曝気処理汚泥の凝集時の発泡現象が起こらなかったことが確認できる。曝気処理を行わない嫌気性処理汚泥は黒色であった。曝気処理汚泥は褐色であり、曝気処理により鉄（II）が鉄（III）に酸化されたことを確認した。曝気処理槽内の汚泥の温度は２４〜３８℃、ＤＯは０．０〜０．１ｍｇ／Ｌ、ＯＲＰ（銀／塩化銀電極を基準としたＯＲＰ）は−１７０〜−３８０ｍＶであった。 From these test results, it was found that the aeration-treated sludge can reduce the cake moisture content, the coagulant injection rate, and the foaming phenomenon when the aeration-treated sludge is agglomerated, as opposed to the anaerobic sludge that is not aerated. It can be confirmed that there was no such thing. The anaerobic treated sludge that was not aerated was black. The aeration-treated sludge was brown, and it was confirmed that iron (II) was oxidized to iron (III) by the aeration treatment. The temperature of the sludge in the aeration treatment tank was 24-38 ° C., the DO was 0.0 to 0.1 mg / L, and the ORP (ORP based on the silver / silver chloride electrode) was -170 to -380 mV.
［実施例７］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。本実施例では、曝気処理汚泥のｐＨを変更し、脱水が効率化されることを確認した。
[Example 7]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. The following tests were conducted in order to confirm that the coagulation is efficient and the dehydration is efficient by forming the coagulated sludge and finally dehydrating the coagulated sludge. In this example, it was confirmed that the pH of the aerated sludge was changed to improve the efficiency of dehydration.
実施例３〜６と同じメタン発酵処理施設（施設Ｆ２）にて、種々の食品製造廃棄物の混合物を可溶化処理した可溶化物を原料とし、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が２００ｍｇ／Ｌ（鉄換算）になるように可溶化物貯槽に鉄化合物を注入し、嫌気性処理を行った。次に、２０Ｌの曝気処理槽に１０Ｌの嫌気性処理汚泥を投入し、温度３５℃、曝気風量０．１ｍ３‐Ａｉｒ／（ｍ３‐汚泥・ｍｉｎ）で、９時間、曝気処理した。次に、曝気処理汚泥に硫酸を注入し、ｐＨを調整した。アミジン系高分子凝集剤でサンプリングした曝気処理汚泥を凝集させ、ベルトプレス脱水機で脱水した。 At the same methane fermentation treatment facility (facility F2) as in Examples 3 to 6, iron in anaerobic treated sludge after injection of an iron compound is used as a raw material, which is a solubilized product obtained by solubilizing a mixture of various food production wastes. An iron compound was injected into a solubilized product storage tank so that the concentration became 200 mg / L (iron equivalent), and anaerobic treatment was performed. Next, 10 L of anaerobic treated sludge was put into a 20 L aeration treatment tank, and aeration treatment was performed at a temperature of 35 ° C. and an aeration air volume of 0.1 m 3- Air / (m 3- sludge / min) for 9 hours. Next, sulfuric acid was injected into the aerated sludge to adjust the pH. The aeration-treated sludge sampled with an amidine-based polymer flocculant was aggregated and dehydrated with a belt press dehydrator.
比較例として、曝気処理汚泥のｐＨを調整しない汚泥に対しても、同様に試験を行った。ｐＨを調整しない汚泥のｐＨは８.６であった。表７に試験結果を示す。 As a comparative example, the same test was conducted on sludge in which the pH of the aerated sludge was not adjusted. The pH of the sludge without adjusting the pH was 8.6. Table 7 shows the test results.
これらの試験結果から、曝気処理汚泥のｐＨを調整することにより、ケーキ含水率を低減できることが確認できた。曝気処理槽内の汚泥のＤＯは、０．０〜０．１ｍｇ／Ｌ、ＯＲＰ（銀／塩化銀電極を基準としたＯＲＰ）は−２４０〜−３１０ｍＶであった。 From these test results, it was confirmed that the moisture content of the cake can be reduced by adjusting the pH of the aerated sludge. The DO of the sludge in the aeration treatment tank was 0.0 to 0.1 mg / L, and the ORP (ORP based on the silver / silver chloride electrode) was -240 to -310 mV.
［実施例８］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。本実施例では、非アミジン系高分子凝集剤である、ジメチルアミノエチルアクリレートの４級塩とアクリルアミドの共重合体（アクリレート系高分子凝集剤）を使用した。
[Example 8]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. The following tests were conducted in order to confirm that the coagulation is efficient and the dehydration is efficient by forming the coagulated sludge and finally dehydrating the coagulated sludge. In this example, a copolymer of a quaternary salt of dimethylaminoethyl acrylate and acrylamide (acrylate-based polymer flocculant), which is a non-amidine-based polymer flocculant, was used.
実施例３〜７と同じメタン発酵処理施設（施設Ｆ２）にて、種々の食品製造廃棄物の混合物を可溶化処理した可溶化物を原料とし、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が２００ｍｇ／Ｌ（鉄換算）になるように可溶化物貯槽に鉄化合物を注入し、嫌気性処理を行った。次に、２０Ｌの曝気処理槽に１０Ｌの嫌気性処理汚泥を投入し、温度３５℃、曝気風量０．３ｍ３‐Ａｉｒ／（ｍ３‐汚泥・ｍｉｎ）で、２４時間、曝気処理した。次に、アクリレート系高分子凝集剤でサンプリングした曝気処理汚泥を凝集させ、ベルトプレス脱水機で脱水した。 At the same methane fermentation treatment facility (facility F2) as in Examples 3 to 7, iron in anaerobic treated sludge after injection of an iron compound is used as a raw material, which is a solubilized product obtained by solubilizing a mixture of various food production wastes. An iron compound was injected into a solubilized product storage tank so that the concentration became 200 mg / L (iron equivalent), and anaerobic treatment was performed. Next, 10 L of anaerobic treated sludge was put into a 20 L aeration treatment tank, and aeration treatment was performed at a temperature of 35 ° C. and an aeration air volume of 0.3 m 3- Air / (m 3- sludge / min) for 24 hours. Next, the aeration-treated sludge sampled with the acrylate-based polymer flocculant was aggregated and dehydrated with a belt press dehydrator.
比較例として、曝気処理をしない汚泥に対しても、同様に試験を行った。表８に試験結果を示す。 As a comparative example, the same test was conducted on sludge that was not aerated. Table 8 shows the test results.
これらの試験結果から、アクリレート系高分子凝集剤で曝気処理汚泥を凝集させることによって、ケーキ含水率を低減できることが確認できた。曝気処理を行わない嫌気性処理汚泥は黒色であったが、２４時間以上の曝気時間で嫌気性処理汚泥は褐色に変化し、曝気処理により鉄（II）が鉄（III）に酸化されたことを確認した。曝気処理槽内の汚泥のＤＯは、０．０〜０．１ｍｇ／Ｌ、ＯＲＰ（銀／塩化銀電極を基準としたＯＲＰ）は−２５０〜−３３０ｍＶであった。 From these test results, it was confirmed that the moisture content of the cake can be reduced by aggregating the aeration-treated sludge with an acrylate-based polymer flocculant. The anaerobic treated sludge without aeration treatment was black, but the anaerobic treated sludge turned brown after an aeration time of 24 hours or more, and iron (II) was oxidized to iron (III) by the aeration treatment. It was confirmed. The DO of the sludge in the aeration treatment tank was 0.0 to 0.1 mg / L, and the ORP (ORP based on the silver / silver chloride electrode) was -250 to -330 mV.
［実施例９］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。本実施例では、非アミジン系高分子凝集剤である、ジメチルアミノエチルメタクリレートの４級塩の重合体（メタクリレート系高分子凝集剤）を使用した。
[Example 9]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. The following tests were conducted in order to confirm that the coagulation is efficient and the dehydration is efficient by forming the coagulated sludge and finally dehydrating the coagulated sludge. In this example, a polymer of a quaternary salt of dimethylaminoethyl methacrylate (methacrylate-based polymer flocculant), which is a non-amidine-based polymer flocculant, was used.
実施例３〜８と同じメタン発酵処理施設（施設Ｆ２）にて、種々の食品製造廃棄物の混合物を可溶化処理した可溶化物を原料とし、鉄化合物注入後の嫌気性処理汚泥中の鉄濃度が２００ｍｇ／Ｌ（鉄換算）になるように可溶化物貯槽に鉄化合物を注入し、嫌気性処理を行った。次に、２０Ｌの曝気処理槽に１０Ｌの嫌気性処理汚泥を投入し、温度３５℃、曝気風量０．３ｍ３‐Ａｉｒ／（ｍ３‐汚泥・ｍｉｎ）で、２４時間、曝気処理した。次に、メタクリレート系高分子凝集剤でサンプリングした曝気処理汚泥を凝集させ、ベルトプレス脱水機で脱水した。 At the same methane fermentation treatment facility (facility F2) as in Examples 3 to 8, iron in anaerobic treated sludge after injection of an iron compound is used as a raw material, which is a solubilized product obtained by solubilizing a mixture of various food production wastes. An iron compound was injected into a solubilized product storage tank so that the concentration became 200 mg / L (iron equivalent), and anaerobic treatment was performed. Next, 10 L of anaerobic treated sludge was put into a 20 L aeration treatment tank, and aeration treatment was performed at a temperature of 35 ° C. and an aeration air volume of 0.3 m 3- Air / (m 3- sludge / min) for 24 hours. Next, the aeration-treated sludge sampled with the methacrylate-based polymer flocculant was aggregated and dehydrated with a belt press dehydrator.
比較例として、曝気処理をしない汚泥に対しても、同様に試験を行った。表９に試験結果を示す。 As a comparative example, the same test was conducted on sludge that was not aerated. Table 9 shows the test results.
これらの試験結果から、メタクリレート系高分子凝集剤で曝気処理汚泥を凝集させることによって、ケーキ含水率を低減できることが確認できた。曝気処理を行わない嫌気性処理汚泥は黒色であったが、２４時間の曝気時間で嫌気性処理汚泥は褐色に変化し、曝気処理により鉄（II）が鉄（III）に酸化されたことを確認した。曝気処理槽内の汚泥のＤＯは、０．０〜０．１ｍｇ／Ｌ、ＯＲＰ（銀／塩化銀電極を基準としたＯＲＰ）は−２５０〜−３３０ｍＶであった。 From these test results, it was confirmed that the moisture content of the cake can be reduced by aggregating the aeration-treated sludge with a methacrylate-based polymer flocculant. The anaerobic treated sludge without aeration treatment was black, but the anaerobic treated sludge turned brown after 24 hours of aeration, and iron (II) was oxidized to iron (III) by the aeration treatment. confirmed. The DO of the sludge in the aeration treatment tank was 0.0 to 0.1 mg / L, and the ORP (ORP based on the silver / silver chloride electrode) was -250 to -330 mV.
［実施例１０］
鉄化合物を注入して嫌気性処理を行い、嫌気性処理汚泥を形成させ、次に嫌気性処理汚泥を曝気処理し、曝気処理汚泥を形成させ、次に凝集剤で曝気処理汚泥を凝集させ、凝集汚泥を形成させ、最後に凝集汚泥を脱水することにより、凝集が効率化されること、脱水が効率化されることを確認するため、以下の試験を行った。試験方法は以下の通りである。
[Example 10]
An iron compound is injected to perform anaerobic treatment to form anaerobic treated sludge, then the anaerobic treated sludge is aerated to form aerated sludge, and then the aerated sludge is aerated with a flocculant. The following tests were conducted in order to confirm that the coagulation is efficient and the dehydration is efficient by forming the coagulated sludge and finally dehydrating the coagulated sludge. The test method is as follows.
実施例１及び実施例２と同じメタン発酵処理施設（施設Ｆ１）にて、種々の食品製造廃棄物の混合物を可溶化処理した可溶化物を原料とし、鉄化合物を注入した後の嫌気性処理汚泥中の鉄濃度が２００ｍｇ／Ｌ（鉄換算）になるように可溶化貯槽に鉄化合物を注入し、嫌気性処理を行った。鉄化合物として、ポリ硫酸第二鉄を使用した。実施例３と同じメタン発酵処理施設（施設Ｆ２）でも同様に嫌気性処理を行った。 In the same methane fermentation treatment facility (facility F1) as in Examples 1 and 2, anaerobic treatment after injecting an iron compound using a solubilized product obtained by solubilizing a mixture of various food production wastes as a raw material. An iron compound was injected into the solubilized storage tank so that the iron concentration in the sludge was 200 mg / L (iron equivalent), and anaerobic treatment was performed. Ferric polysulfate was used as the iron compound. The same anaerobic treatment was performed in the same methane fermentation treatment facility (facility F2) as in Example 3.
曝気処理には、メタン発酵処理施設Ｆ１で採取した嫌気性処理汚泥（汚泥Ａ）、メタン発酵処理施設Ｆ２で異なる日時に採取した複数の嫌気性処理汚泥（汚泥Ｂ、汚泥Ｃ、汚泥Ｄ）を使用した。また、比較例として、下水処理場Ｓ１から採取した嫌気性処理汚泥（汚泥Ｅ）、下水処理場Ｓ２から採取した嫌気性処理汚泥（汚泥Ｆ）を使用した。 For aeration treatment, anaerobic treated sludge (sludge A) collected at the methane fermentation treatment facility F1 and a plurality of anaerobic treated sludges (sludge B, sludge C, sludge D) collected at different dates and times at the methane fermentation treatment facility F2 are used. used. Further, as comparative examples, anaerobic treated sludge (sludge E) collected from the sewage treatment plant S1 and anaerobic treated sludge (sludge F) collected from the sewage treatment plant S2 were used.
曝気処理では、２０Ｌの曝気処理槽に１０Ｌの嫌気性処理汚泥を投入し、温度３５℃で曝気した。曝気処理汚泥をサンプリングし、高分子凝集剤を注入して凝集させた後、ベルトプレス脱水機で脱水した。 In the aeration treatment, 10 L of anaerobic treated sludge was put into a 20 L aeration treatment tank and aerated at a temperature of 35 ° C. The aeration-treated sludge was sampled, and after injecting a polymer flocculant to coagulate it, it was dehydrated with a belt press dehydrator.
各汚泥の性状、曝気処理条件、脱水条件及びケーキ含水率を表１０に示す。ＴＳ及びＳＳの分析はＪＩＳ Ｋ−０１０２に準拠し、粘度はＢ型回転粘度計を使用し、３５℃、６０ｒｐｍで測定した。 Table 10 shows the properties of each sludge, aeration treatment conditions, dehydration conditions, and cake moisture content. The analysis of TS and SS was based on JIS K-012, and the viscosity was measured at 35 ° C. and 60 rpm using a B-type rotational viscometer.
これらの結果から、ＴＳ濃度が２５ｇ／Ｌ以上のＴＳと、該ＴＳ濃度よりも５ｇ／Ｌ以上低いＳＳ濃度とを有する嫌気性処理汚泥を曝気処理することにより、ケーキ含水率を低減できることを確認した。 From these results, it was confirmed that the cake moisture content can be reduced by aerating the anaerobic treated sludge having a TS concentration of 25 g / L or more and an SS concentration of 5 g / L or more lower than the TS concentration. did.
Claims (4)
嫌気性処理汚泥に酸素含有気体を接触させ、曝気処理汚泥を形成させる曝気処理工程と、
曝気処理汚泥に凝集剤を注入し、凝集汚泥を形成させる凝集工程を有し、
前記嫌気性処理工程の前もしくは嫌気性処理工程において、前記有機物に鉄化合物を注入し、
前記曝気処理工程において、前記曝気性処理汚泥の酸化還元電位（銀／塩化銀電極を基準とした酸化還元電位）を−４００ｍＶ以上−１００ｍＶ以下かつ前記曝気処理汚泥の溶存酸素濃度を１．０ｍｇ／Ｌ以下に制御し、鉄化合物を含有する嫌気性処理汚泥と酸素含有気体とを接触させることにより、嫌気性処理汚泥に含まれる鉄（II）を酸化させ、嫌気性処理汚泥に含まれる凝集阻害成分を生物的あるいは化学的に分解し
酸化された鉄（III）を前記凝集工程において凝集剤として利用することを特徴とする有機物の処理方法。 An anaerobic treatment process that anaerobicizes organic matter and forms anaerobic treatment sludge,
An aeration treatment process in which an oxygen-containing gas is brought into contact with the anaerobic treatment sludge to form an aeration treatment sludge,
It has a coagulation step in which a coagulant is injected into aeration-treated sludge to form coagulated sludge.
Before the anaerobic treatment step or in the anaerobic treatment step, an iron compound is injected into the organic substance.
In the aeration process, the dissolved oxygen concentration in the oxidation-reduction potential (silver / silver chloride electrode was used as a reference oxidation-reduction potential) of -400mV or more -100mV or less and the aeration sludge of the aeration of sludge 1.0 mg / By controlling the temperature to L or less and bringing the anaerobic treated sludge containing an iron compound into contact with an oxygen-containing gas, the iron (II) contained in the anaerobic treated sludge is oxidized and aggregation inhibition contained in the anaerobic treated sludge. A method for treating an organic substance, which comprises using iron (III), which is oxidized by biologically or chemically decomposing a component, as a coagulant in the coagulation step.
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