JP2007021289A - Method for treating nitrate nitrogen-containing water - Google Patents
Method for treating nitrate nitrogen-containing water Download PDFInfo
- Publication number
- JP2007021289A JP2007021289A JP2005203125A JP2005203125A JP2007021289A JP 2007021289 A JP2007021289 A JP 2007021289A JP 2005203125 A JP2005203125 A JP 2005203125A JP 2005203125 A JP2005203125 A JP 2005203125A JP 2007021289 A JP2007021289 A JP 2007021289A
- Authority
- JP
- Japan
- Prior art keywords
- containing water
- nitrate nitrogen
- catalyst
- nitrate
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 172
- MMDJDBSEMBIJBB-UHFFFAOYSA-N [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[NH6+3] Chemical compound [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[NH6+3] MMDJDBSEMBIJBB-UHFFFAOYSA-N 0.000 title claims abstract description 121
- 238000000034 method Methods 0.000 title claims abstract description 63
- 239000002245 particle Substances 0.000 claims abstract description 101
- 239000003054 catalyst Substances 0.000 claims abstract description 99
- 238000011282 treatment Methods 0.000 claims abstract description 84
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 75
- 229910052751 metal Inorganic materials 0.000 claims abstract description 64
- 239000002184 metal Substances 0.000 claims abstract description 64
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 52
- 239000007789 gas Substances 0.000 claims abstract description 36
- 230000001603 reducing effect Effects 0.000 claims abstract description 34
- 150000001722 carbon compounds Chemical class 0.000 claims abstract description 6
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 5
- 239000010439 graphite Substances 0.000 claims abstract description 5
- 229920000049 Carbon (fiber) Polymers 0.000 claims abstract description 4
- 239000006230 acetylene black Substances 0.000 claims abstract description 4
- 239000004917 carbon fiber Substances 0.000 claims abstract description 4
- 229910021393 carbon nanotube Inorganic materials 0.000 claims abstract description 4
- 239000002041 carbon nanotube Substances 0.000 claims abstract description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000002116 nanohorn Substances 0.000 claims abstract description 4
- 239000013078 crystal Substances 0.000 claims abstract description 3
- 239000010419 fine particle Substances 0.000 claims description 74
- 229910045601 alloy Inorganic materials 0.000 claims description 39
- 239000000956 alloy Substances 0.000 claims description 39
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 18
- 229910052763 palladium Inorganic materials 0.000 claims description 16
- 229910052802 copper Inorganic materials 0.000 claims description 11
- 229910002651 NO3 Inorganic materials 0.000 claims description 9
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 7
- 229910052737 gold Inorganic materials 0.000 claims description 7
- 239000011164 primary particle Substances 0.000 claims description 7
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 229910052697 platinum Inorganic materials 0.000 claims description 6
- 229910052709 silver Inorganic materials 0.000 claims description 6
- 229910052721 tungsten Inorganic materials 0.000 claims description 6
- 229910052720 vanadium Inorganic materials 0.000 claims description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- 150000002739 metals Chemical class 0.000 claims description 4
- 238000003672 processing method Methods 0.000 claims description 3
- 229910052727 yttrium Inorganic materials 0.000 claims description 2
- 239000011859 microparticle Substances 0.000 claims 1
- 230000009467 reduction Effects 0.000 abstract description 11
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 24
- 239000006185 dispersion Substances 0.000 description 22
- 239000003638 chemical reducing agent Substances 0.000 description 19
- 230000000694 effects Effects 0.000 description 17
- 238000011156 evaluation Methods 0.000 description 14
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 13
- 239000001257 hydrogen Substances 0.000 description 13
- 229910052739 hydrogen Inorganic materials 0.000 description 13
- 230000002829 reductive effect Effects 0.000 description 13
- 239000007864 aqueous solution Substances 0.000 description 12
- 239000010949 copper Substances 0.000 description 12
- 238000002360 preparation method Methods 0.000 description 12
- 230000007423 decrease Effects 0.000 description 11
- 238000000354 decomposition reaction Methods 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 8
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 8
- 150000003839 salts Chemical class 0.000 description 8
- 229910002668 Pd-Cu Inorganic materials 0.000 description 7
- 239000006229 carbon black Substances 0.000 description 7
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 7
- 229910052757 nitrogen Inorganic materials 0.000 description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 239000003273 ketjen black Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 239000011790 ferrous sulphate Substances 0.000 description 4
- 235000003891 ferrous sulphate Nutrition 0.000 description 4
- 239000010931 gold Substances 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 4
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 4
- 238000011068 loading method Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 239000010944 silver (metal) Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 239000002351 wastewater Substances 0.000 description 4
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- JVMRPSJZNHXORP-UHFFFAOYSA-N ON=O.ON=O.ON=O.N Chemical compound ON=O.ON=O.ON=O.N JVMRPSJZNHXORP-UHFFFAOYSA-N 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 3
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- SXTLQDJHRPXDSB-UHFFFAOYSA-N copper;dinitrate;trihydrate Chemical compound O.O.O.[Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O SXTLQDJHRPXDSB-UHFFFAOYSA-N 0.000 description 3
- 230000018109 developmental process Effects 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- 239000012299 nitrogen atmosphere Substances 0.000 description 3
- 229910017464 nitrogen compound Inorganic materials 0.000 description 3
- JUBNUQXDQDMSKL-UHFFFAOYSA-N palladium(2+);dinitrate;dihydrate Chemical compound O.O.[Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O JUBNUQXDQDMSKL-UHFFFAOYSA-N 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 229910001961 silver nitrate Inorganic materials 0.000 description 3
- 239000001509 sodium citrate Substances 0.000 description 3
- 239000003381 stabilizer Substances 0.000 description 3
- HRXKRNGNAMMEHJ-UHFFFAOYSA-K trisodium citrate Chemical compound [Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O HRXKRNGNAMMEHJ-UHFFFAOYSA-K 0.000 description 3
- 229940038773 trisodium citrate Drugs 0.000 description 3
- AZQWKYJCGOJGHM-UHFFFAOYSA-N 1,4-benzoquinone Chemical compound O=C1C=CC(=O)C=C1 AZQWKYJCGOJGHM-UHFFFAOYSA-N 0.000 description 2
- KWSLGOVYXMQPPX-UHFFFAOYSA-N 5-[3-(trifluoromethyl)phenyl]-2h-tetrazole Chemical compound FC(F)(F)C1=CC=CC(C2=NNN=N2)=C1 KWSLGOVYXMQPPX-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 229910017827 Cu—Fe Inorganic materials 0.000 description 2
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 2
- 229910018883 Pt—Cu Inorganic materials 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000004931 aggregating effect Effects 0.000 description 2
- 229910003481 amorphous carbon Inorganic materials 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 239000003651 drinking water Substances 0.000 description 2
- 235000020188 drinking water Nutrition 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000000909 electrodialysis Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000004108 freeze drying Methods 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 230000002209 hydrophobic effect Effects 0.000 description 2
- 239000010842 industrial wastewater Substances 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 230000008929 regeneration Effects 0.000 description 2
- 238000011069 regeneration method Methods 0.000 description 2
- 238000001223 reverse osmosis Methods 0.000 description 2
- 229910052707 ruthenium Inorganic materials 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000012279 sodium borohydride Substances 0.000 description 2
- 229910000033 sodium borohydride Inorganic materials 0.000 description 2
- 229910001379 sodium hypophosphite Inorganic materials 0.000 description 2
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 229910001252 Pd alloy Inorganic materials 0.000 description 1
- 229910021065 Pd—Fe Inorganic materials 0.000 description 1
- 229910002839 Pt-Mo Inorganic materials 0.000 description 1
- 229910018885 Pt—Au Inorganic materials 0.000 description 1
- 230000010757 Reduction Activity Effects 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007596 consolidation process Methods 0.000 description 1
- XPPWAISRWKKERW-UHFFFAOYSA-N copper palladium Chemical compound [Cu].[Pd] XPPWAISRWKKERW-UHFFFAOYSA-N 0.000 description 1
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000010335 hydrothermal treatment Methods 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 229910052809 inorganic oxide Inorganic materials 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 1
- YJVFFLUZDVXJQI-UHFFFAOYSA-L palladium(ii) acetate Chemical compound [Pd+2].CC([O-])=O.CC([O-])=O YJVFFLUZDVXJQI-UHFFFAOYSA-L 0.000 description 1
- CLSUSRZJUQMOHH-UHFFFAOYSA-L platinum dichloride Chemical compound Cl[Pt]Cl CLSUSRZJUQMOHH-UHFFFAOYSA-L 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- OJLCQGGSMYKWEK-UHFFFAOYSA-K ruthenium(3+);triacetate Chemical compound [Ru+3].CC([O-])=O.CC([O-])=O.CC([O-])=O OJLCQGGSMYKWEK-UHFFFAOYSA-K 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000004317 sodium nitrate Substances 0.000 description 1
- 235000010344 sodium nitrate Nutrition 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 238000000108 ultra-filtration Methods 0.000 description 1
Landscapes
- Treatment Of Water By Oxidation Or Reduction (AREA)
- Catalysts (AREA)
Abstract
Description
本発明は、硝酸性窒素含有水の処理方法に関し、さらに詳しくは、硝酸性窒素含有水を還元剤の存在下に触媒と接触させて硝酸性窒素を還元分解する硝酸性窒素含有水の処理方法に関する。 The present invention relates to a method for treating nitrate nitrogen-containing water, and more specifically, a method for treating nitrate nitrogen-containing water by reductively decomposing nitrate nitrogen by bringing nitrate nitrogen-containing water into contact with a catalyst in the presence of a reducing agent. About.
従来、排水等の中に含まれる硝酸性窒素を除去する処理方法としては、微生物による生物学的処理方法、吸着法、イオン交換法、逆浸透膜法、電気透析法などの物理化学的処理方法および水素などの還元剤の存在下に硝酸性窒素を触媒と接触させて還元分解する化学的処理方法などが知られている。特に、硝酸性窒素を還元剤の存在下に触媒と接触させて還元分解する化学的処理方法は低濃度の硝酸性窒素を含む飲料水の原水や高濃度の硝酸性窒素を含む工業排水など、大量の硝酸性窒素含有水から硝酸性窒素を除去するのに適しており、種々の処理方法が提案されている。 Conventional treatment methods for removing nitrate nitrogen contained in wastewater, etc. include biological treatment methods using microorganisms, adsorption methods, ion exchange methods, reverse osmosis membrane methods, electrodialysis methods, and other physicochemical treatment methods. Also known is a chemical treatment method in which nitrate nitrogen is brought into contact with a catalyst in the presence of a reducing agent such as hydrogen to perform reductive decomposition. In particular, chemical treatment methods in which nitrate nitrogen is brought into contact with a catalyst in the presence of a reducing agent for reductive decomposition include raw water for drinking water containing low concentrations of nitrate nitrogen and industrial wastewater containing high concentrations of nitrate nitrogen, etc. It is suitable for removing nitrate nitrogen from a large amount of nitrate nitrogen-containing water, and various treatment methods have been proposed.
例えば、本願出願人にかかる特開２００４−９７８９３号公報（特許文献１）には、無機酸化物担体および／またはカーボン担体に、Ｐｔ、Ａｕ、Ａｇ、Ｐｄ、Ｒｕ、Ｃｕ、Ｎｉ、Ｗ、Ｖ、Ｍｏ、Ｆｅから選ばれる１種または２種以上の金属微粒子および／または合金微粒子が担持されてなる、平均粒子径が５ｎｍ〜２０μｍの範囲にある硝酸性窒素含有水処理用触媒が記載されており、更に、硝酸性窒素含有水処理方法として、
（ａ）前述の水処理用触媒と硝酸性窒素含有水とを、還元剤の存在下で接触させる工程
（ｂ）前記接触済の硝酸性窒素含有水から水処理用触媒を分離する工程
（ｃ）必要に応じて前記分離した水処理用触媒を再生し、工程（ａ）に戻す工程
からなる硝酸性窒素含有水処理方法が開示されている。
For example, in Japanese Patent Application Laid-Open No. 2004-97893 (Patent Document 1) according to the present applicant, Pt, Au, Ag, Pd, Ru, Cu, Ni, W, V are added to the inorganic oxide support and / or the carbon support. A nitrate nitrogen-containing water treatment catalyst having an average particle diameter in the range of 5 nm to 20 μm, on which one or more metal fine particles and / or alloy fine particles selected from Mo, Fe, are supported is described. In addition, as a method for treating nitrate nitrogen-containing water,
(A) a step of bringing the water treatment catalyst and nitrate nitrogen-containing water into contact with each other in the presence of a reducing agent (b) a step of separating the water treatment catalyst from the contacted nitrate nitrogen-containing water (c) ) A nitrate nitrogen-containing water treatment method comprising a step of regenerating the separated water treatment catalyst as necessary and returning to the step (a) is disclosed.
また、本願出願人は特開２００４−５７９５４号公報（特許文献２）として、Ａｕ、Ａｇ、Ｐｔ、Ｐｄ、Ｒｈ、Ｃｕ、Ｆｅ、Ｎｉ、Ｃｏ、Ｓｎ、Ｉｎ、Ｔｉ、Ａｌ、Ｔａ、Ｓｂ、Ｒｕから選ばれる１種または２種以上の金属からなる金属微粒子であって、平均粒子径が１〜２００ｎｍの範囲にある硝酸性窒素含有水処理用触媒を開示している。 In addition, the applicant of the present application disclosed in Japanese Patent Application Laid-Open No. 2004-57954 (Patent Document 2), Au, Ag, Pt, Pd, Rh, Cu, Fe, Ni, Co, Sn, In, Ti, Al, Ta, Sb, A nitrate nitrogen-containing water treatment catalyst is disclosed which is a metal fine particle composed of one or more metals selected from Ru and having an average particle diameter in the range of 1 to 200 nm.
特開２００１−８６６号公報（特許文献３）には、原水中の硝酸性窒素および亜硝酸性窒素を、触媒を用いて水素で還元分解するにあたり、金属パラジウムと、元素比がＣｕ≧Ｐｄである銅−パラジウム合金との混合物を触媒とする水処理方法が記載されている。
特開平８−１９２１６９号公報（特許文献４）には、硝酸性窒素とアンモニア性窒素を含む排水中の硝酸性窒素を、水中で水素を発生する金属と接触させることにより、亜硝酸性窒素または窒素ガスまで還元し、溶出した金属を軟化処理によって除去した後、生成した亜硝酸性窒素およびアンモニア性窒素を触媒存在下で反応させ、窒素に転換する硝酸性窒素およびアンモニア性窒素を含む排水の処理方法が記載されている。
In Japanese Patent Laid-Open No. 2001-866 (Patent Document 3), when reducing and decomposing nitrate nitrogen and nitrite nitrogen in raw water with hydrogen using a catalyst, the elemental ratio is Cu ≧ Pd. A water treatment method using a mixture with a certain copper-palladium alloy as a catalyst is described.
In JP-A-8-192169 (Patent Document 4), nitrate nitrogen in waste water containing nitrate nitrogen and ammonia nitrogen is brought into contact with a metal that generates hydrogen in water, thereby producing nitrite nitrogen or After reducing to nitrogen gas and removing the eluted metal by softening treatment, the generated nitrite nitrogen and ammonia nitrogen are reacted in the presence of a catalyst to convert the waste water containing nitrate nitrogen and ammonia nitrogen into nitrogen. A processing method is described.
このような状況下、さらに高活性な硝酸性窒素含有水処理用触媒の開発とともに、効率的なプロセスの開発が望まれている。
本発明の目的は、低濃度の硝酸性窒素を含む飲料水の原水や、高濃度の硝酸性窒素を含む工業排水など大量の硝酸性窒素含有水から硝酸性窒素を除去する硝酸性窒素含有水の処理方法において、硝酸性窒素の還元速度を高めると共に還元ガスの利用率を向上させることのできる硝酸性窒素含有水の処理方法を提供することにある。 An object of the present invention is to remove nitrate nitrogen from a large amount of nitrate nitrogen-containing water such as raw water of drinking water containing low-concentration nitrate nitrogen or industrial wastewater containing high-concentration nitrate nitrogen. It is an object of the present invention to provide a method for treating nitrate-containing water that can increase the reduction rate of nitrate nitrogen and improve the utilization rate of reducing gas.
本発明は、硝酸性窒素含有水と水処理触媒とを還元ガスの存在下で接触させる硝酸性窒素含有水の処理方法において、前記水処理触媒が結晶性炭素粒子に金属微粒子が担持された平均粒子径が５ｎｍ〜１μｍの範囲の微粒子からなり、触媒微粒子中の金属微粒子の担持量が金属として１〜５０重量％の範囲にあることを特徴とするものである。 The present invention provides a method for treating nitrate nitrogen-containing water in which nitrate nitrogen-containing water and a water treatment catalyst are contacted in the presence of a reducing gas, wherein the water treatment catalyst is an average in which metal fine particles are supported on crystalline carbon particles. It consists of fine particles having a particle diameter in the range of 5 nm to 1 μm, and the supported amount of metal fine particles in the catalyst fine particles is in the range of 1 to 50% by weight as metal.
前記金属は、Ｐt、Ａu、Ａg、Ｐd、Ｒu、Ｃu、Ｎi、Ｗ、Ｖ、Ｍo、Ｆe、Ｙから選ばれる１種または２種以上の金属または合金であることが好ましく、特に、少なくともＰdとＣuとを含む金属または合金であることが好ましい。
前記金属微粒子の平均粒子径は１〜５０ｎｍの範囲にあることが好ましい。
前記結晶性炭素粒子の平均粒子径（一次粒子径）は５〜５００ｎｍの範囲にあることが好ましく、前記結晶性炭素粒子の比表面積は２０〜３０００ｍ2／ｇの範囲にあることが好ましい。
The metal is preferably one or more metals or alloys selected from Pt, Au, Ag, Pd, Ru, Cu, Ni, W, V, Mo, Fe, and Y, in particular at least Pd. It is preferably a metal or alloy containing Cu and Cu.
The average particle size of the metal fine particles is preferably in the range of 1 to 50 nm.
The average particle diameter (primary particle diameter) of the crystalline carbon particles is preferably in the range of 5 to 500 nm, and the specific surface area of the crystalline carbon particles is preferably in the range of 20 to 3000 m 2 / g.
前記結晶性炭素粒子の結晶構造はグラファイト構造であり、結晶子径が２〜１００ｎｍの範囲であり、かつ結晶子間距離が０．３４０〜０．３６２ｎｍの範囲にあることが好ましく、前記結晶性炭素粒子は、カーボンブラック、アセチレンブラック、カーボンナノチューブ、カーボンナノホーン、カーボンファイバー、黒鉛から選ばれる１種または２種以上の結晶性炭素化合物からなることが好ましい。
前記還元ガスは、平均直径０．１ｍｍ以下の超微細気泡水素ガスであることが好ましい。
The crystal structure of the crystalline carbon particles is a graphite structure, the crystallite diameter is preferably in the range of 2 to 100 nm, and the crystallite distance is preferably in the range of 0.340 to 0.362 nm. The carbon particles are preferably composed of one or more crystalline carbon compounds selected from carbon black, acetylene black, carbon nanotube, carbon nanohorn, carbon fiber, and graphite.
The reducing gas is preferably ultrafine bubble hydrogen gas having an average diameter of 0.1 mm or less.
本発明の硝酸性窒素含有水の処理方法では、比表面積の高い結晶性炭素粒子に平均粒子径の小さい金属微粒子を担持した水処理触媒を用いるので、硝酸性窒素還元活性が高い。また、結晶性炭素粒子が疎水性を有しているので処理水と容易に分離することができ、このため効率的に硝酸性窒素を還元分解することができる。 In the method for treating nitrate nitrogen-containing water of the present invention, since a water treatment catalyst in which metal fine particles having a small average particle diameter are supported on crystalline carbon particles having a high specific surface area is used, nitrate nitrogen reduction activity is high. Further, since the crystalline carbon particles have hydrophobicity, they can be easily separated from the treated water, and therefore nitrate nitrogen can be efficiently reduced and decomposed.
以下、本発明の硝酸性窒素含有水の処理方法について具体的に説明する。
硝酸性窒素含有水
本発明に用いる硝酸性窒素含有水としては、水中の硝酸性窒素化合物の濃度がＮとして５０〜１０，０００ｐｐｍ、さらには、１００〜５０００ｐｐｍの範囲にあることが好ましい。ここで、硝酸性窒素化合物とはＮＯ3、ＮＯ2、ＮＯ、Ｎ2Ｏを含む化合物の総称である。
処理水中の硝酸性窒素化合物の濃度がＮとして５０ｐｐｍ未満の場合は、還元分解処理することは可能であるが経済性が問題となることがある。濃度がＮとして１０，０００ｐｐｍを越えると、やはり、還元分解処理することは可能であるが還元剤（還元ガス）の使用量が多くなり経済性が問題となることがある。
このため、本発明の方法は他の吸着法、イオン交換法、逆浸透膜法、電気透析法、あるいは生物脱窒法等と併用することが好ましい場合がある。
Hereinafter, the method for treating nitrate nitrogen-containing water of the present invention will be described in detail.
The nitrate nitrogen-containing water to be used for nitrate nitrogen-containing water present invention, 50～10,000Ppm as the concentration of nitrate nitrogen compound in water is N, further preferably in the range of 100 to 5000 ppm. Here, the nitrate nitrogen compound is a general term for compounds containing NO 3 , NO 2 , NO, and N 2 O.
When the concentration of the nitrate nitrogen compound in the treated water is less than 50 ppm as N, reductive decomposition treatment is possible, but economic efficiency may be a problem. If the concentration exceeds 10,000 ppm as N, it is still possible to carry out reductive decomposition treatment, but the amount of reducing agent (reducing gas) used increases, which may cause a problem of economy.
For this reason, the method of the present invention may be preferably used in combination with other adsorption methods, ion exchange methods, reverse osmosis membrane methods, electrodialysis methods, biological denitrification methods, and the like.
硝酸性窒素含有水処理用触媒
本発明において硝酸性窒素含有水処理用触媒は、金属微粒子が結晶性炭素粒子に担持されてなり、平均粒子径が５ｎｍ〜１μｍの範囲にある。
前記金属微粒子としては、Ｐt、Ａu、Ａg、Ｐd、Ｒu、Ｃu、Ｎi、Ｗ、Ｖ、Ｍo、Ｆe、またはＹから選ばれる１種または２種以上の金属または合金が好ましい。好ましい２成分以上の組み合わせとしては、Ｐd-Ｃu、Ｐd-Ａu、Ｐd-Ｗ、Ｐd-Ｖ、Ｐd-Ｍo、Ｐd-Ｆe、Ｐd-Ｃu／Ｐd、Ｐd-Ｃu-Ｒu、Ｐd-Ｃu-Ｆe、Ｐd-Ｃu-Ａu、Ｐt-Ｃu、Ｐt-Ａu、Ｐt-Ｗ、Ｐt-Ｖ、Ｐt-Ｍo、Ｐt-Ｆe、Ｐt-Ｃu／Ｐd、Ｐt-Ｃu-Ｒu、Ｐt-Ｃu-Ｆe、Ｐt-Ｃu-Ａu等が挙げられる。このような金属微粒子は、硝酸性窒素を還元して分解する活性が高く、且つ活性劣化が小さく、また再生によって容易に活性が復元し、長期にわたって活性を維持することができる。
Nitrate nitrogen-containing water treatment catalyst In the present invention, the nitrate nitrogen-containing water treatment catalyst has metal fine particles supported on crystalline carbon particles, and has an average particle diameter in the range of 5 nm to 1 μm.
The metal fine particles are preferably one or more metals or alloys selected from Pt, Au, Ag, Pd, Ru, Cu, Ni, W, V, Mo, Fe, or Y. Preferred combinations of two or more components include Pd-Cu, Pd-Au, Pd-W, Pd-V, Pd-Mo, Pd-Fe, Pd-Cu / Pd, Pd-Cu-Ru, Pd-Cu-Fe , Pd-Cu-Au, Pt-Cu, Pt-Au, Pt-W, Pt-V, Pt-Mo, Pt-Fe, Pt-Cu / Pd, Pt-Cu-Ru, Pt-Cu-Fe, Pt -Cu-Au and the like. Such metal fine particles have a high activity for reducing and decomposing nitrate nitrogen, have a small activity deterioration, can be easily restored by regeneration, and can maintain the activity over a long period of time.
なお、ここで合金とは、２種以上の金属成分が均一に混合しているもの（上記において例えば「Ｐd-Ｃu」と表記）に限らず、混合物であるもの（上記において「Ｃu／Ｐd」と表記）も含んで意味している。また、これらの金属成分は結晶性であっても非晶質であってもよい。
このなかでもＣuとＰdおよび／またはＰtからなる合金微粒子は、還元剤である水素の吸着能が高くかつ常温で硝酸性窒素をＮ2とＨ2Ｏに選択的に還元分解するので、特に好ましい。
Here, the alloy is not limited to an alloy in which two or more kinds of metal components are uniformly mixed (for example, expressed as “Pd—Cu” in the above), but an alloy (in the above, “Cu / Pd”). This also includes These metal components may be crystalline or amorphous.
Of these, alloy fine particles comprising Cu and Pd and / or Pt are particularly preferred because they have a high ability to adsorb hydrogen as a reducing agent and selectively reduce and decompose nitrate nitrogen to N 2 and H 2 O at room temperature. .
金属微粒子の平均粒子径は１〜５０ｎｍ、さらには１〜１０ｎｍの範囲にあることが好ましい。平均粒子径が１ｎｍ未満の場合は、初期性能は高いが、再生等を繰り返すことによって移動して他の金属微粒子と凝集する傾向があり、長期にわたって初期性能を維持することが困難である。平均粒子径が５０ｎｍを越えると、還元剤の吸着量が低下するとともに水素の活性化能も低下し、硝酸性窒素の還元分解活性が低下する。
金属微粒子の粒子径は、例えば、ＦＥ-ＴＥＭ（ＳＴＥＭ-ＨＡＡＤＦ法）により測定することができる。
The average particle diameter of the metal fine particles is preferably in the range of 1 to 50 nm, more preferably 1 to 10 nm. When the average particle size is less than 1 nm, the initial performance is high, but it tends to move and aggregate with other metal fine particles by repeating regeneration and the like, and it is difficult to maintain the initial performance over a long period of time. If the average particle diameter exceeds 50 nm, the amount of reducing agent adsorbed decreases, the hydrogen activation ability also decreases, and the reductive decomposition activity of nitrate nitrogen decreases.
The particle diameter of the metal fine particles can be measured by, for example, FE-TEM (STEM-HAADF method).
前記結晶性炭素粒子としては、カーボンブラック、アセチレンブラック、カーボンナノチューブ、カーボンナノホーン、カーボンファイバー、黒鉛などが挙げられる。このような結晶性炭素粒子は金属微粒子との結合力が強く、処理中の金属の処理液への溶出を抑制することができ、また担体から容易に脱離することがなく、このため長期処理が可能である。
一方、活性炭のような無定形炭素粒子（非結晶性炭素粒子）は、化学的安定性、機械的強度（安定性）が低い上に、粒子径が大きく親水性が高い場合があり、本発明の水処理用触媒の担体としては、不適当である。
Examples of the crystalline carbon particles include carbon black, acetylene black, carbon nanotube, carbon nanohorn, carbon fiber, and graphite. Such crystalline carbon particles have a strong binding force with the metal fine particles, can suppress elution of the metal being processed into the processing solution, and do not easily desorb from the carrier, and thus can be treated for a long time. Is possible.
On the other hand, amorphous carbon particles (non-crystalline carbon particles) such as activated carbon have low chemical stability and mechanical strength (stability) and may have a large particle size and high hydrophilicity. It is unsuitable as a carrier for water treatment catalysts.
結晶性炭素粒子の平均粒子径（一次粒子径）は５〜５００ｎｍ、さらには１０〜１００ｎｍの範囲にあることが好ましい。平均粒子径（一次粒子径）が５ｎｍ未満の場合は、結晶性が低いためか、前記結晶性炭素粒子を用いる効果が不充分となる傾向がある。平均粒子径（一次粒子径）が５００ｎｍを超えると、比表面積が低く、金属微粒子を高分散した状態に担持することができないために、即ち、担体表面で金属微粒子が凝集した状態となるため充分な活性が得られないことがある。
なお、ここで結晶性炭素粒子の平均粒子径を一次粒子径と規定したのは、水処理用触媒の担体として用いる結晶性炭素粒子は、概ね触媒の粒子径と同じく平均粒子径が５ｎｍ〜１μｍの範囲にあれば凝集体であっても非凝集体であってもよく、このときの非凝集体を一次粒子として意味したものである。
The average particle diameter (primary particle diameter) of the crystalline carbon particles is preferably in the range of 5 to 500 nm, more preferably 10 to 100 nm. When the average particle size (primary particle size) is less than 5 nm, the effect of using the crystalline carbon particles tends to be insufficient because of low crystallinity. When the average particle diameter (primary particle diameter) exceeds 500 nm, the specific surface area is low, and the metal fine particles cannot be supported in a highly dispersed state, that is, the metal fine particles are aggregated on the support surface. Activity may not be obtained.
Here, the average particle diameter of the crystalline carbon particles is defined as the primary particle diameter because the average particle diameter of the crystalline carbon particles used as the carrier of the catalyst for water treatment is approximately 5 nm to 1 μm, similar to the particle diameter of the catalyst. In this range, it may be an aggregate or a non-aggregate, and the non-aggregate at this time is meant as a primary particle.
結晶性炭素粒子の比表面積は２０〜３０００ｍ2／ｇ、さらには５００〜２０００ｍ2／ｇの範囲にあることが好ましい。比表面積が２０ｍ2／ｇ未満の場合は、所定量の金属微粒子を担持した場合、金属微粒子が結晶性炭素粒子の表面で凝集した状態となるため充分な活性が得られないことがある。比表面積が３０００ｍ2／ｇを超えるものは、微粒子の集合体であり、結晶性が低く、硝酸性窒素の酸化還元活性や後述する疎水性等の結晶性炭素粒子を用いる効果が不充分となる傾向がある。 The specific surface area of crystalline carbon particles 20~3000m 2 / g, more preferably in the range of 500~2000m 2 / g. When the specific surface area is less than 20 m 2 / g, when a predetermined amount of metal fine particles is supported, the metal fine particles are aggregated on the surface of the crystalline carbon particles, so that sufficient activity may not be obtained. Those having a specific surface area exceeding 3000 m 2 / g are aggregates of fine particles, have low crystallinity, and the effect of using crystalline carbon particles such as redox activity of nitrate nitrogen and hydrophobicity described later is insufficient. Tend.
前記結晶性炭素粒子は充分な疎水性を有していることが好ましい。担体として用いる結晶性炭素粒子が疎水性であると、反応終了後あるいは必要に応じて反応を停止した後、処理水表面に触媒が分離して浮遊し、触媒を特別の装置（例えばセラミックスフィルター等）を用いることなく分離することが可能である。特に微細な粒子では、通常の方法で分離が困難であっても、容易に分離することができる。先に列挙したものは、疎水性の結晶性炭素粒子である。
なお、結晶性炭素粒子の粒子径が大きく、通常の方法で容易に分離できる場合には、結晶性炭素粒子を硝酸などの酸で処理して親水性にして用いることも可能である。
It is preferable that the crystalline carbon particles have sufficient hydrophobicity. If the crystalline carbon particles used as a support are hydrophobic, the catalyst is separated and floated on the surface of the treated water after the reaction is completed or stopped as necessary. ) Can be used for separation. In particular, fine particles can be easily separated even if separation by a normal method is difficult. Listed above are hydrophobic crystalline carbon particles.
In addition, when the particle diameter of the crystalline carbon particles is large and can be easily separated by a usual method, the crystalline carbon particles can be treated with an acid such as nitric acid to be made hydrophilic.
本発明に用いる結晶性炭素粒子はＸ線回折によりグラファイト構造を有し、結晶子径が２〜１００ｎｍ、さらには２〜４０ｎｍの範囲にあり、結晶子間距離が０．３４０〜０．３６２ｎｍ、さらには０．３４２〜０．３６０ｎｍの範囲にあることが好ましい。
結晶子径が２ｎｍ未満の場合は、結晶性炭素粒子の結晶性が低すぎて化学的或いは機械的安定性が劣り、所望の撥水性が得られ難い。結晶子径が１００ｎｍを超えると、結晶性炭素粒子の結晶性が高すぎて比表面積が低下し、この結果、担持する金属微粒子の量および分散性が低下して、所望の活性が得られ難い。
結晶子間距離が０．３４０ｎｍ未満になると結晶性が高すぎるために比表面積が低下して担持する金属微粒子が凝集し易くなる。結晶子間距離が０．３６２ｎｍを超えたものは結晶性が不充分で、硝酸性窒素の還元活性や後述する疎水性等の結晶性炭素粒子を用いる効果が不充分となる傾向がある。
The crystalline carbon particles used in the present invention have a graphite structure by X-ray diffraction, have a crystallite diameter of 2 to 100 nm, more preferably 2 to 40 nm, and a distance between crystallites of 0.340 to 0.362 nm, Furthermore, it is preferable that it exists in the range of 0.342-0.360 nm.
When the crystallite diameter is less than 2 nm, the crystallinity of the crystalline carbon particles is too low, the chemical or mechanical stability is inferior, and the desired water repellency is difficult to obtain. When the crystallite diameter exceeds 100 nm, the crystallinity of the crystalline carbon particles is too high and the specific surface area is lowered. As a result, the amount and dispersibility of the supported metal fine particles are lowered, and it is difficult to obtain a desired activity. .
When the distance between crystallites is less than 0.340 nm, the crystallinity is too high, so that the specific surface area is reduced and the supported metal fine particles are easily aggregated. When the distance between crystallites exceeds 0.362 nm, the crystallinity is insufficient, and the reducing activity of nitrate nitrogen and the effect of using crystalline carbon particles such as hydrophobicity described later tend to be insufficient.
前記結晶子間距離の測定法では、Ｘ線回折により、グラファイト構造に基づく［０，０，２］面の垂直方向であるＣ軸方向の格子定数Ｃを求め、このＣの１／２を層間距離として表す。
また、本発明の結晶子径の測定法は、Ｘ線回折により、メインピーク［０．０．２］面（格子定数ｄ＝３．３７５６、ミラー指数ｈ＝０、ｋ＝０、ｌ＝２）の半価幅（β）より、Scherrerの式Ｄ＝λ／βｃｏｓθ（Ｄ：結晶子径、λ＝Ｘ線波長（Å）、θ＝反射角）により求めることができる。
In the method for measuring the distance between crystallites, the lattice constant C in the C-axis direction, which is the vertical direction of the [0, 0, 2] plane based on the graphite structure, is obtained by X-ray diffraction, and ½ of this C is calculated as an interlayer. Expressed as distance.
The crystallite diameter measurement method of the present invention is performed by X-ray diffraction using a main peak [0.0.2] plane (lattice constant d = 3.3756, Miller index h = 0, k = 0, l = 2. ) At half-value width (β), Scherrer's equation D = λ / βcos θ (D: crystallite diameter, λ = X-ray wavelength (Å), θ = reflection angle).
本発明に係る硝酸性窒素含有水処理用触媒は、平均粒子径が５ｎｍ〜１μｍ、さらには１０ｎｍ〜０．５μｍの範囲にあることが好ましい。
触媒微粒子の平均粒子径が５ｎｍ未満のものは、凝集する傾向が強く、触媒の調製が困難であったり、得られたとしても凝集して分散性が低下し、硝酸性窒素含有水の処理効率が低下することがある。平均粒子径が１μｍを越えると、硝酸性窒素含有水の循環あるいは撹拌が弱くなると沈降することがあり、また硝酸性窒素との接触効率が低下して充分な還元分解活性が得られず、硝酸性窒素の低減が不充分となる。
The nitrate nitrogen-containing water treatment catalyst according to the present invention preferably has an average particle size in the range of 5 nm to 1 μm, more preferably 10 nm to 0.5 μm.
When the average particle size of the catalyst fine particles is less than 5 nm, the tendency to agglomerate is strong, and it is difficult to prepare the catalyst. May decrease. If the average particle diameter exceeds 1 μm, precipitation may occur if the circulation or stirring of nitrate-nitrogen-containing water is weak, and contact efficiency with nitrate-nitrogen will decrease, resulting in insufficient reductive decomposition activity. The reduction of reactive nitrogen is insufficient.
硝酸性窒素含有水処理用触媒中の金属微粒子の担持量は、金属として１〜５０重量％、さらには２〜２０重量％の範囲にあることが好ましい。担持量が１重量％未満の場合は、還元分解活性が不充分となる。担持量が５０重量％を越えると、担持することが困難であるとともに、仮に担持できても還元分解活性がさらに向上することもないので、経済性が低下する。また、担持した金属微粒子同士が互いに合体して粒子成長することがあり、活性が低下することがある。 The supported amount of the metal fine particles in the nitrate nitrogen-containing water treatment catalyst is preferably in the range of 1 to 50% by weight, more preferably 2 to 20% by weight as the metal. When the loading is less than 1% by weight, the reductive decomposition activity is insufficient. When the loading amount exceeds 50% by weight, it is difficult to carry, and even if it can be carried, the reductive decomposition activity is not further improved, so the economic efficiency is lowered. In addition, the supported metal fine particles may coalesce with each other to grow particles, which may reduce the activity.
硝酸性窒素含有水処理用触媒の製造方法
このような硝酸性窒素含有水処理用触媒微粒子は、前記した粒子径範囲にあり、水に分散し、沈降等することなく硝酸性窒素と効率的に接触し、充分な還元分解活性が得られれば特に制限はなく、従来公知の方法を用いて製造することができる。
以下、本発明に用いることのできる硝酸性窒素含有水処理用触媒の製造方法を３つ例示的に説明する。
Method for Producing Nitrate Nitrogen-Containing Water Treatment Catalyst Such fine particles of nitrate nitrogen-containing water treatment are in the above-mentioned particle size range, and are efficiently dispersed with nitrate nitrogen without being dispersed, settled, etc. in water. If it contacts and sufficient reductive decomposition activity is obtained, there will be no restriction | limiting in particular, It can manufacture using a conventionally well-known method.
Hereinafter, three methods for producing a nitrate nitrogen-containing water treatment catalyst that can be used in the present invention will be described.
（第１の製造方法）
前記した結晶性炭素粒子の分散液を調製する。これに、所定量の１種または２種以上の金属塩水溶液を加え、結晶性炭素粒子に金属塩水溶液を吸収させ、次いで乾燥し、その後２００〜８００℃の温度で、還元ガス例えばＨ2、ＮＨ3雰囲気下で通常０．５〜６時間程度還元処理することによって硝酸性窒素含有水処理用触媒微粒子を得ることができる。
金属塩としては、硝酸パラジウム、塩化パラジウム、酢酸パラジウム、テトラアンミンパラジウム、塩化白金、硝酸銀、塩化銅、硝酸ニッケル、酢酸ルテニウムなど、前記した金属の塩で水に可溶な塩を用いることができる。
(First manufacturing method)
A dispersion of the crystalline carbon particles described above is prepared. A predetermined amount of one or more metal salt aqueous solutions are added thereto, the crystalline carbon particles absorb the metal salt aqueous solution, and then dried, and then at a temperature of 200 to 800 ° C., a reducing gas such as H 2 , By carrying out reduction treatment for about 0.5 to 6 hours under NH 3 atmosphere, nitrate nitrogen-containing catalyst fine particles for water treatment can be obtained.
As the metal salt, water-soluble salts such as palladium nitrate, palladium chloride, palladium acetate, tetraammine palladium, platinum chloride, silver nitrate, copper chloride, nickel nitrate, and ruthenium acetate can be used.
乾燥方法としては、凍結乾燥、噴霧乾燥、静置乾燥、ロータリーエバポレーター等、従来公知の方法を採用することができる。
上記において、還元温度が２００℃未満の時は、金属塩の還元が不充分となり、金属微粒子の生成が不充分となる。還元温度が８００℃を越えると、金属微粒子が粒子成長しすぎたり、触媒粒子が強く凝集して分散性が低下することがあり、本発明に係る粒子径の小さな触媒粒子を用いた硝酸性窒素含有水の安定的な処理が困難となる。好ましい還元温度は２５０〜６００℃の範囲である。
As a drying method, conventionally known methods such as freeze drying, spray drying, stationary drying, and rotary evaporator can be employed.
In the above, when the reduction temperature is less than 200 ° C., the reduction of the metal salt is insufficient and the generation of metal fine particles is insufficient. If the reduction temperature exceeds 800 ° C., the metal fine particles may grow too much, or the catalyst particles may be strongly aggregated and the dispersibility may be reduced. Nitrate nitrogen using catalyst particles having a small particle diameter according to the present invention Stable treatment of the contained water becomes difficult. A preferable reduction temperature is in the range of 250 to 600 ° C.
（第２の製造方法）
前記した結晶性炭素粒子の分散液を調製する。これに、所定量の１種または２種以上の金属塩水溶液を加え、ついで還元剤（水素化硼素ナトリウム（ＮaＢＨ4）、次亜リン酸ソーダ、ヒドラジン等）を加え、結晶性炭素粒子上に金属を析出させる。ついで、必要に応じてオートクレーブ処理（１００〜３００℃で水熱処理）する。オートクレーブ処理により、溶液中に析出した金属微粒子を結晶性炭素粒子上に析出させることができる。
最後に金属微粒子が担持された結晶性炭素粒子を濾過分離し、第１の方法と同様にして乾燥した後、加熱処理（好ましくは不活性ガスまたは還元ガス雰囲気下で加熱処理）することによって硝酸性窒素含有水処理用触媒を得ることができる。
(Second manufacturing method)
A dispersion of the crystalline carbon particles described above is prepared. A predetermined amount of one or more metal salt aqueous solutions are added, and then a reducing agent (sodium borohydride (NaBH 4 ), sodium hypophosphite, hydrazine, etc.) is added to the crystalline carbon particles. Deposit metal. Then, autoclaving (hydrothermal treatment at 100 to 300 ° C.) is performed as necessary. By the autoclave treatment, the metal fine particles deposited in the solution can be deposited on the crystalline carbon particles.
Finally, the crystalline carbon particles carrying the metal fine particles are separated by filtration, dried in the same manner as in the first method, and then heat-treated (preferably heat-treated in an inert gas or reducing gas atmosphere) to form nitric acid. A catalyst for treatment of water containing nitrogen can be obtained.
（第３の製造方法）
例えば、パラジウム−銅合金の微粒子であれば、硝酸パラジウムと硝酸銅との混合水溶液に、クエン酸の水溶液に還元剤として硫酸第一鉄を溶解した溶液を添加して、Ｐd-Ｃu合金微粒子分散液を調製する。このＰd-Ｃu合金微粒子分散液に結晶性炭素粒子の分散液を混合してＰd-Ｃu合金微粒子を結晶性炭素粒子担体に担持した触媒微粒子分散液を調製する。なお、このときの担持は、互いの粒子のゼータ電位の差あるいは積により、結晶性炭素粒子の表面にＰd-Ｃu合金微粒子が担持されるものであって、金属微粒子のゼータ電位は負、結晶性炭素粒子のゼータ電位は正または負である。
(Third production method)
For example, in the case of fine particles of palladium-copper alloy, a solution in which ferrous sulfate is dissolved as a reducing agent in an aqueous solution of citric acid is added to a mixed aqueous solution of palladium nitrate and copper nitrate to disperse the fine particles of Pd—Cu alloy. Prepare the solution. A dispersion of crystalline carbon particles is mixed with the Pd—Cu alloy fine particle dispersion to prepare a catalyst fine particle dispersion in which the Pd—Cu alloy fine particles are supported on a crystalline carbon particle carrier. In this case, the loading is such that the Pd—Cu alloy fine particles are supported on the surface of the crystalline carbon particles by the difference or product of the zeta potentials of the particles, and the zeta potential of the metal fine particles is negative, The zeta potential of the conductive carbon particles is positive or negative.
さらに具体的に説明すると、異種粒子間のヘテロ凝集は、２つのゼータ電位値が異符号であるか、その差が大きい場合は当然凝集作用が起こる。即ち、本発明の場合は結晶性炭素粒子担体に合金微粒子が担持される。また、２つのゼータ電位値が同符号であっても、ゼータ電位の積が臨界表面電位より小さい場合は凝集作用が起こる。即ち、本発明の場合は結晶性炭素粒子担体に合金微粒子が担持される。
最後に金属微粒子が担持された結晶性炭素粒子を濾過分離し、第１の方法と同様にして乾燥し、ついで加熱処理（好ましくは不活性ガスまたは還元ガス雰囲気下で加熱処理）することによって硝酸性窒素含有水処理用触媒を得る。
More specifically, heteroaggregation between different kinds of particles naturally causes an aggregating action when the two zeta potential values have different signs or the difference between them is large. That is, in the case of the present invention, alloy fine particles are supported on the crystalline carbon particle carrier. Even if the two zeta potential values have the same sign, an aggregating action occurs when the product of the zeta potential is smaller than the critical surface potential. That is, in the case of the present invention, alloy fine particles are supported on the crystalline carbon particle carrier.
Finally, the crystalline carbon particles carrying the metal fine particles are separated by filtration, dried in the same manner as in the first method, and then heat-treated (preferably heat-treated in an inert gas or reducing gas atmosphere) to form nitric acid. A catalyst for treatment of water containing nitrogen is obtained.
上記各製造方法によって、平均粒子径が５ｎｍ〜１μｍ、さらには１０ｎｍ〜０．５μｍの範囲にある硝酸性窒素含有水処理用触媒が得られる。
また、触媒微粒子中の金属微粒子の含有量は１〜５０重量％、さらには２〜２０重量％の範囲とすることができる。
By each of the above production methods, a nitrate nitrogen-containing water treatment catalyst having an average particle size in the range of 5 nm to 1 μm, and further 10 nm to 0.5 μm is obtained.
Further, the content of the metal fine particles in the catalyst fine particles can be in the range of 1 to 50% by weight, and further 2 to 20% by weight.
硝酸性窒素含有水の処理
本発明の硝酸性窒素含有水の処理方法は、前記したように、硝酸性窒素含有水と前記水処理触媒とを超微細気泡還元ガスの存在下で接触させることが好ましい。
そこで、この超微細気泡還元ガスについて説明する。
Treatment of Nitrate Nitrogen-Containing Water As described above, the method for treating nitrate-nitrogen-containing water according to the present invention comprises contacting nitrate-nitrogen-containing water and the water treatment catalyst in the presence of ultrafine bubble reducing gas. preferable.
Therefore, the ultrafine bubble reducing gas will be described.
本発明に用いる還元ガスとしては、電気分解で容易に製造することができ、必要に応じて回収することができる等の点から水素ガスが好適に採用される。
超微細気泡還元ガスは、大きさが平均値で０．１ｍｍ以下、概ね０．０５〜１００μｍ、さらには５０μｍ以下、特に３０μｍ以下であることが好ましい。超微細気泡還元ガスの大きさが０．１ｍｍを超えると還元ガスの硝酸性窒素含有水への溶解速度が遅くなるためか、硝酸性窒素の還元速度（処理速度）が遅くなるとともに還元ガスの利用率が低下し、処理効率が低下するとともに経済性が低下する。ここで、還元ガスの利用率とは供給した還元ガスの内、硝酸性窒素の還元に用いられた還元ガスの割合をいう。
また、超微細気泡還元ガスの大きさが平均値で０．０５μｍ未満のものは現在のところ得ることが困難である。
As the reducing gas used in the present invention, hydrogen gas is preferably employed from the viewpoint that it can be easily produced by electrolysis and can be recovered as required.
The ultrafine bubble reducing gas has an average value of 0.1 mm or less, generally 0.05 to 100 μm, more preferably 50 μm or less, and particularly preferably 30 μm or less. If the size of the ultrafine bubble reducing gas exceeds 0.1 mm, the rate of dissolution of the reducing gas in the nitrate nitrogen-containing water slows, or the rate of reduction of nitrate nitrogen (treatment rate) slows and the reducing gas The utilization rate decreases, the processing efficiency decreases, and the economic efficiency decreases. Here, the utilization rate of the reducing gas refers to the ratio of the reducing gas used for reducing nitrate nitrogen in the supplied reducing gas.
Also, it is difficult to obtain an ultrafine bubble reducing gas having an average value of less than 0.05 μm on average.
このような水中における気泡の大きさの測定方法は、例えば、水中パーティクルカウンター（リオン（株）製：ＫＲ−３２またはＫＲ−６０）等によって測定することができる。
なお、本発明では前記水素ガス以外に必要に応じて、別途ヒドラジン、水素化硼素ナトリウム、次亜リン酸ナトリウム、キノン、ヒドロキノン等の還元剤を硝酸性窒素含有水に添加して用いることもできる。
Such a method for measuring the size of bubbles in water can be measured by, for example, an underwater particle counter (manufactured by Lion Co., Ltd .: KR-32 or KR-60).
In the present invention, a reducing agent such as hydrazine, sodium borohydride, sodium hypophosphite, quinone, hydroquinone and the like can be separately added to the nitrate nitrogen-containing water as necessary in addition to the hydrogen gas. .
本発明の硝酸性窒素含有水の処理方法に用いる処理設備の方式には特に制限はなく、前記した超微細気泡還元ガスを発生させ供給できる設備を備えていれば従来公知の方式を採用することができ、例えば、完全混合槽型や、流通型、多段型、バッチ型等の種々の方式がある。これらは、通常の撹拌装置、循環装置等を備えている。 There is no particular limitation on the method of treatment equipment used in the method for treating nitrate nitrogen-containing water of the present invention, and a conventionally known method should be adopted as long as it has equipment capable of generating and supplying the ultrafine bubble reducing gas described above. For example, there are various methods such as a complete mixing tank type, a distribution type, a multistage type, and a batch type. These are equipped with a normal stirring device, a circulation device and the like.
超微細気泡還元ガス発生・供給装置としては前記した大きさの気泡を供給できれば特に制限はなく、例えば(1)多孔質板に圧力をかけて微細気泡を発生させる方法、(2)微小径ノズルから気体を噴出し微細気泡を発生させる方法、(3)単管の壁面に突起を設けて気体を衝突させて微細気泡を発生させる方法、(4)気体、液体の噴流間の不安定性を利用する方法、(5)流体で旋回流を作り、気体と共に放出させて微細気泡を発生させる方法などがある。
中でも(1)または(2)の方法は好適である。具体的には、例えば、スキルキット（株）製の超微細気泡発生装置、資源開発（株）製のＡＷＡＷＡなどが好適に使用できる。
The ultrafine bubble reducing gas generating / supplying device is not particularly limited as long as it can supply bubbles of the above-described size. For example, (1) a method of generating fine bubbles by applying pressure to a porous plate, (2) a fine diameter nozzle A method of generating fine bubbles by ejecting gas from a gas, (3) A method of generating protrusions on the wall of a single tube and causing gas to collide, and (4) Instability between gas and liquid jets And (5) creating a swirl flow with a fluid and releasing it with a gas to generate fine bubbles.
Of these, the method (1) or (2) is preferred. Specifically, for example, an ultrafine bubble generating device manufactured by Skill Kit Co., Ltd., AWAWA manufactured by Resource Development Co., Ltd. and the like can be suitably used.
硝酸性窒素含有水中の硝酸性窒素含有水処理用触媒の濃度は０．０５〜２０重量％、さらには０．１〜１０重量％の範囲にあることが好ましい。触媒濃度が０．０５重量％未満の場合は、処理温度が常温以下の場合に還元分解速度が不充分で、硝酸性窒素を所望の濃度以下に低減することが困難となる。触媒濃度が２０重量％を超えると、濃度が高過ぎて処理還元ガスの分散性が低下して処理効率が低下したり、触媒の使用量が多過ぎて経済性が問題となることがある。 The concentration of the nitrate nitrogen-containing water treatment catalyst in the nitrate nitrogen-containing water is preferably 0.05 to 20% by weight, more preferably 0.1 to 10% by weight. When the catalyst concentration is less than 0.05% by weight, the reductive decomposition rate is insufficient when the treatment temperature is room temperature or lower, and it is difficult to reduce nitrate nitrogen below the desired concentration. If the catalyst concentration exceeds 20% by weight, the concentration may be too high and the dispersibility of the treatment reducing gas may be lowered to lower the treatment efficiency, or the amount of catalyst used may be too high, resulting in a problem of economy.
本発明の処理方法において、硝酸性窒素含有水と水処理用触媒との接触時間（滞留時間）は、処理を必要とする水の量および水中の硝酸性窒素の濃度、要求される処理水（清浄水）中のＮ濃度レベル、処理温度、触媒中の金属微粒子の量、粒子径、処理水のｐＨや不純物の他処理方法・装置等によって異なるが、概ね１００時間以下、通常１０分間〜２５時間の範囲にあることが好ましい。 In the treatment method of the present invention, the contact time (retention time) between the nitrate nitrogen-containing water and the water treatment catalyst is the amount of water that requires treatment, the concentration of nitrate nitrogen in the water, the required treated water ( N concentration level in clean water), treatment temperature, amount of metal fine particles in catalyst, particle diameter, pH of treated water and other treatment methods / devices of impurities, etc., but generally 100 hours or less, usually 10 minutes to 25 It is preferably in the time range.
また、還元剤（還元ガス）の供給量は、要求される処理後の残存窒素濃度によっても異なるが、下記化学反応式（１）に示されるように、概ね水硝酸性窒素と還元剤との量論量以上であればよく、例えば硝酸性窒素がＮＯ3の場合、本発明の処理方法では、還元剤のモル数（ＭR）と硝酸性窒素（ＮＯ3）のモル数（ＭN）と比（ＭR／ＭN）が３〜１５、さらには３〜６の範囲にあることが好ましい。
２ＮＯ3 ＋ ６Ｈ2 → Ｎ2 ＋ ６Ｈ2Ｏ ・・・（１）
前記モル比が３未満の場合は還元剤が少ないために、得られる処理後の水（清浄水）中の硝酸性窒素濃度が高く、所期の目的を達成できないことがあり、モル比が１５を越えると、ＮＨ3の生成が増加したり還元剤の利用率が低下し、さらに、還元剤を回収する場合でも回収量が多くなり経済性が低下する。
In addition, although the supply amount of the reducing agent (reducing gas) varies depending on the required residual nitrogen concentration after the treatment, as shown in the following chemical reaction formula (1), the amount of water nitrate nitrogen and the reducing agent is roughly For example, when nitrate nitrogen is NO 3 , in the treatment method of the present invention, the number of moles of reducing agent (M R ) and the number of moles of nitrate nitrogen (NO 3 ) (M N ). And the ratio (M R / M N ) is preferably in the range of 3 to 15, more preferably 3 to 6.
2NO 3 + 6H 2 → N 2 + 6H 2 O (1)
When the molar ratio is less than 3, since there are few reducing agents, the concentration of nitrate nitrogen in the resulting treated water (clean water) is high, and the intended purpose may not be achieved. If it exceeds 1, the production of NH 3 will increase or the utilization rate of the reducing agent will decrease, and even when the reducing agent is recovered, the recovered amount will increase and the economic efficiency will decrease.
なお、還元処理する際は、必要に応じて酸またはアルカリを添加してｐＨ調整し、ｐＨ３〜１０、さらには４〜９の範囲とすることが好ましい。
硝酸性窒素含有水のｐＨが３未満の場合は、触媒中の金属微粒子の金属が溶出し、活性が低下したり、処理水中に金属が含まれたり、酸性であるためにそのまま排水とすることができない等の問題が生じることがある。硝酸性窒素含有水のｐＨが１０を越えると、硝酸性窒素の還元速度が遅くなるとともにＮＨ3の副生が増加する傾向がある。
In addition, when carrying out a reduction process, it is preferable to add an acid or an alkali as needed, and to adjust pH to pH 3-10, Furthermore, it is preferable to be the range of 4-9.
If the pH of the nitrate nitrogen-containing water is less than 3, the metal particles in the catalyst elute and the activity decreases, the metal is contained in the treated water, or it is acidic, so it should be used as wastewater. Problems such as inability to do so may occur. When the pH of the nitrate nitrogen-containing water exceeds 10, the reduction rate of nitrate nitrogen tends to be slow and NH 3 by-product tends to increase.
本発明の硝酸性窒素含有水の処理方法では、前記還元ガスの利用率が３０〜１００％、さらには５０〜１００％の範囲にあることが好ましい。還元ガスの利用率が３０％未満の場合は、処理後の水（清浄水）中の硝酸性窒素の残存濃度が高く、所期の目的を達成できない場合や、経済性が問題となる。未利用の還元ガスは回収して再度利用することができる。 In the method for treating nitrate-nitrogen-containing water of the present invention, it is preferable that the utilization rate of the reducing gas is in the range of 30 to 100%, more preferably 50 to 100%. When the utilization rate of the reducing gas is less than 30%, the residual concentration of nitrate nitrogen in the treated water (clean water) is high, and the intended purpose cannot be achieved, or the economy becomes a problem. Unused reducing gas can be recovered and reused.
所望の濃度に処理した処理水は、処理水と触媒を分離し、触媒はそのまま繰り返し使用することができるが、必要に応じて再生して用いることもできる。
処理水と触媒とを分離する方法としては限外濾過膜、セラミックフィルター等を用いた方法を採用することができる。特に流通式セラミックフィルターは口径を触媒粒子径に応じて選択することができるので効率的に分離することができ、またフィルターの圧密化などによる口径の変化がなく、耐久性に優れているので好ましい。
The treated water treated to a desired concentration separates the treated water and the catalyst, and the catalyst can be used repeatedly as it is, but can be regenerated and used as necessary.
As a method for separating the treated water and the catalyst, a method using an ultrafiltration membrane, a ceramic filter or the like can be employed. In particular, a flow-through ceramic filter is preferable because it can be separated efficiently because the diameter can be selected according to the catalyst particle diameter, and there is no change in the diameter due to the consolidation of the filter, etc., and it is excellent in durability. .
このようにして処理された処理水中のＮ濃度（硝酸性Ｎおよび副生することのあるアンモニア性Ｎの合計）は１００ｐｐｍ以下、好ましくは１０ｐｐｍ以下であることが好ましい。
なお、下記化学反応式（２）に示されるように、硝酸性窒素含有水の処理によって副生することのあるＮＨ3ガスは、必要に応じてアンモニアストリッピング等、従来公知の方法によって除去することができる。
２ＮＯ3 ＋ ９Ｈ2 → ２ＮＨ3 ＋ ６Ｈ2Ｏ ・・・（２）
以下に示す実施例により、本発明をさらに具体的に説明するが、本発明はこれら実施例に限定されるものではない。
The N concentration in the treated water thus treated (the total of nitrate N and ammoniacal N which may be by-produced) is 100 ppm or less, preferably 10 ppm or less.
In addition, as shown in the following chemical reaction formula (2), NH 3 gas that may be by-produced by the treatment of nitrate nitrogen-containing water is removed by a conventionally known method such as ammonia stripping as necessary. be able to.
2NO 3 + 9H 2 → 2NH 3 + 6H 2 O (2)
The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.
触媒(1)の調製
純水１００ｇに、合金微粒子を構成するパラジウムと銅の重量比が７０／３０となるように硝酸パラジウム２水和塩7.4ｇ及び硝酸銅３水和塩４.９ｇを溶解した金属塩水溶液に、安定化剤として濃度30重量％のクエン酸三ナトリウム水溶液２６５ｇと還元剤として濃度２５重量％の硫酸第一鉄水溶液１２９ｇ（硝酸パラジウムと硝酸銅の合計モル数の2倍量のモル数に相当）を加え、窒素雰囲気下で２０時間攪拌して合金微粒子の分散液を得た。合金微粒子の平均粒子径は４ｎｍであった。
Preparation of catalyst (1) In 100 g of pure water, 7.4 g of palladium nitrate dihydrate and 4.9 g of copper nitrate trihydrate are dissolved so that the weight ratio of palladium and copper constituting the alloy fine particles is 70/30. 265 g of a 30 wt% trisodium citrate aqueous solution as a stabilizer and 129 g of a 25 wt% ferrous sulfate aqueous solution as a reducing agent (twice the total number of moles of palladium nitrate and copper nitrate) The mixture was stirred for 20 hours under a nitrogen atmosphere to obtain a dispersion of alloy fine particles. The average particle size of the alloy fine particles was 4 nm.
得られた分散液を遠心分離器により水洗して不純物を除去した後、水に分散させ、濃度１０重量％の合金微粒子(1)の分散液とし、これに結晶性炭素化合物としてカーボンブラック（キャボット（株）製：Vulcan XC-72R、平均粒子径３1ｎｍ、比表面積２３０ｍ2／ｇ、結晶子径３．３ｎｍ）５ｇを純水４９５ｇに均一に混合した分散液を添加し、この混合液のｐＨを６に調整して１時間撹拌した。ついで、この混合液を１００℃で乾燥させ触媒(1)を調製した。触媒(1)の金属担持量は２０重量であった。 The obtained dispersion was washed with water by a centrifugal separator to remove impurities, and then dispersed in water to obtain a dispersion of alloy fine particles (1) having a concentration of 10% by weight, and carbon black (cabot) as a crystalline carbon compound. Co., Ltd .: Vulcan XC-72R, average particle size of 31 nm, specific surface area of 230 m 2 / g, crystallite size of 3.3 nm) was added to a dispersion in which 5 g of pure water was uniformly mixed with 495 g of pure water. Was adjusted to 6 and stirred for 1 hour. Next, this mixed solution was dried at 100 ° C. to prepare catalyst (1). The metal loading of catalyst (1) was 20 weight.
撥水浮遊性の評価
得られた触媒(1)５ｇを１００ｍｌの水に分散させ、２００ｒｐｍで５分間撹拌した後、撹拌を停止し、触媒(1)の浮遊状態を観察し、以下の基準により評価した。結果を触媒の性状と共に表１に示す。
触媒(1)が全量水面上に浮遊していた。：◎
触媒(1)の８０％以上が水面上に浮遊し、他は水中に分散していた。：○
触媒(1)の５０％〜８０％未満が水面上に浮遊し、他は水中に分散していた。：△
触媒(1)の５０未満が水面上に浮遊し、他は水中に分散あるいは沈降していた。：×
Evaluation of water repellency floatability 5 g of the obtained catalyst (1) was dispersed in 100 ml of water, stirred at 200 rpm for 5 minutes, then the stirring was stopped, and the floating state of the catalyst (1) was observed. evaluated. The results are shown in Table 1 together with the properties of the catalyst.
The entire amount of catalyst (1) was floating on the water surface. : ◎
More than 80% of the catalyst (1) floated on the water surface and the others were dispersed in water. : ○
50% to less than 80% of the catalyst (1) floated on the water surface, and the others were dispersed in water. : △
Less than 50 of catalyst (1) floated on the surface of the water, and the others were dispersed or settled in water. : ×
硝酸性窒素含有水の処理
硝酸ナトリウム(関東化学(株)製：特級)６１.３ｇを純水に溶解して硝酸性窒素含有水２５ｋｇを調製した。このときの硝酸性窒素の含有量はＮとして４００ｐｐｍであった。
超微細気泡還元ガス発生装置（スキルキット(株)製：マイクロバブル発生装置）の水槽に硝酸性窒素含有水を投入し、硝酸性窒素含有水を循環させながらこれに触媒(1)１０００ｇを分散させた。このときの硝酸性窒素含有水中の触媒(1)の分散濃度は３．８重量％である。
Treatment of nitrate nitrogen-containing water 61.3 g of sodium nitrate (manufactured by Kanto Chemical Co., Ltd .: special grade) was dissolved in pure water to prepare 25 kg of nitrate nitrogen-containing water. At this time, the content of nitrate nitrogen was 400 ppm as N.
Nitrogen-containing nitrogen-containing water is put into the water tank of an ultrafine bubble reducing gas generator (Skill Kit Co., Ltd .: Microbubble generator), and 1000 g of catalyst (1) is dispersed in this water while circulating nitrate-nitrogen-containing water. I let you. At this time, the dispersion concentration of the catalyst (1) in nitrate nitrogen-containing water is 3.8% by weight.
次いで、水素ガスの超微細気泡を水槽に吹き込み、硝酸性窒素含有水の処理を実施した。この時、液温を２５℃に維持し、水槽は２００ｒｐｍで攪拌した。マイクロバブル発生装置は、液循環量７０Ｌ／ｍｉｎ、液圧力０.４５ＭＰa、水素圧力０.４５ＭＰa とし、水素の流量を０.４８ＮＬ／ｍｉｎの条件で注入し、硝酸性窒素の処理中は、硝酸性窒素含有水のｐＨを濃度１重量％の硫酸にて５〜６の範囲に調整した。このときに発生した水素の超微細気泡（マイクロバブル）の大きさをパーティクルカウンター（リオン(株)製：ＫＲ−３２）により測定したところ、４〜２０μｍ（平均値：１３μｍ）であった。 Next, ultrafine bubbles of hydrogen gas were blown into the water tank to treat the nitrate-containing water. At this time, the liquid temperature was maintained at 25 ° C., and the water tank was stirred at 200 rpm. The microbubble generator has a liquid circulation rate of 70 L / min, a liquid pressure of 0.45 MPa, a hydrogen pressure of 0.45 MPa, a hydrogen flow rate of 0.48 NL / min, and during treatment with nitrate nitrogen, The pH of the basic nitrogen-containing water was adjusted to a range of 5 to 6 with sulfuric acid having a concentration of 1% by weight. The size of hydrogen ultrafine bubbles (microbubbles) generated at this time was measured with a particle counter (manufactured by Rion Co., Ltd .: KR-32), and it was 4 to 20 μm (average value: 13 μm).
水素の超微細気泡を供給開始後、５分毎に処理液を採取し、窒素分析装置（ブランルーベ（株）製：ＡＡＳ−III）により硝酸性窒素（ＮＯ3＋ＮＯ2）およびＮＨ3の分析を行った。
硝酸性窒素の還元は８５分（ＮＯ3＋ＮＯ2が０ｐｐｍとなった時点）で終了し、このときの副生ＮＨ3濃度、水素の供給量、および水素利用率（Ｎ2生成、ＮＨ3副生）、水素未利用率を、処理条件と共に表２に示した。
After supplying the ultrafine bubbles of hydrogen, the processing solution is collected every 5 minutes and analyzed for nitrate nitrogen (NO 3 + NO 2 ) and NH 3 using a nitrogen analyzer (Blanlube Co., Ltd .: AAS-III). went.
The reduction of nitrate nitrogen was completed in 85 minutes (when NO 3 + NO 2 became 0 ppm). At this time, the concentration of by-product NH 3 , the supply amount of hydrogen, and the hydrogen utilization rate (N 2 production, NH 3 Table 2 shows the hydrogen unused rate together with the treatment conditions.
触媒(2)の調製
実施例１において、結晶性炭素化合物としてカーボンブラック（ケッチェンブラックインターナショナル（株）製：ケッチェンブラックＥＣ、平均粒子径３０ｎｍ、比表面積８２０ｍ2／ｇ、結晶子径３．０ｎｍ）を用いた以外は同様にして、触媒(2)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(2)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (2) In Example 1, carbon black (manufactured by Ketjen Black International Co., Ltd .: Ketjen Black EC, average particle size 30 nm, specific surface area 820 m 2 / g, crystallite size 3. Catalyst (2) was prepared in the same manner except that 0 nm) was used.
Treatment of nitrate nitrogen-containing water The nitrate nitrogen-containing water was treated under the same conditions as in Example 1 except that the catalyst (2) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(3)の調製
実施例１において、結晶性炭素化合物としてカーボンブラック（ケッチェンブラックインターナショナル（株）製：ケッチェンブラックＥＣ６００ＪＤ、平均粒子径３１ｎｍ、比表面積１２８０ｍ2／ｇ、結晶子径３．１ｎｍ）を用いた以外は同様にして触媒(3)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(3)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (3) In Example 1, carbon black (manufactured by Ketjen Black International Co., Ltd .: Ketjen Black EC600JD, average particle size 31 nm, specific surface area 1280 m 2 / g, crystallite size 3. Catalyst (3) was prepared in the same manner except that 1 nm) was used.
Treatment of nitrate nitrogen-containing water In Example 1, the nitrate nitrogen-containing water was treated under the same conditions except that the catalyst (3) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(4)の調製
実施例１において、結晶性炭素化合物としてカーボンブラック（電気化学工業（株）製：デンカブラック ＦＸ−３５、平均粒子径２６ｎｍ、比表面積１３３ｍ2／ｇ、結晶子径４．３ｎｍ）を用いた以外は同様にして触媒(4)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(4)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of Catalyst (4) In Example 1, as a crystalline carbon compound, carbon black (manufactured by Denki Kagaku Kogyo Co., Ltd .: Denka Black FX-35, average particle size 26 nm, specific surface area 133 m 2 / g, crystallite size 4. Catalyst (4) was prepared in the same manner except that 3 nm) was used.
Treatment of nitrate nitrogen-containing water In Example 1, the nitrate nitrogen-containing water was treated under the same conditions except that the catalyst (4) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(5)の調製
実施例１において、結晶性炭素化合物としてカーボンブラック（電気化学工業（株）製：デンカブラック ＯＡＢ−１００、平均粒子径３７ｎｍ、比表面積８８ｍ2／ｇ、結晶子径５．７ｎｍ）を用いた以外は同様にして触媒(5)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(5)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (5) In Example 1, carbon black (manufactured by Denki Kagaku Kogyo Co., Ltd .: Denka Black OAB-100, average particle size 37 nm, specific surface area 88 m 2 / g, crystallite size 5. Catalyst (5) was prepared in the same manner except that 7 nm) was used.
Treatment of nitrate nitrogen-containing water The nitrate nitrogen-containing water was treated under the same conditions as in Example 1 except that the catalyst (5) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(6)の調製
実施例３において、合金微粒子を構成するパラジウムと銅の重量比が９０／１０となるように硝酸パラジウムおよび硝酸銅を加えた以外は同様にして、濃度１０重量％の合金微粒子(2)の分散液とした。合金微粒子の平均粒子径は３ｎｍであった。
ついで、合金微粒子(2)の分散液を用いた以外は同様にして触媒(6)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(6)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (6) In Example 3, an alloy having a concentration of 10% by weight was prepared in the same manner as in Example 3 except that palladium nitrate and copper nitrate were added so that the weight ratio of palladium and copper constituting the alloy fine particles was 90/10. A dispersion of fine particles (2) was obtained. The average particle size of the alloy fine particles was 3 nm.
Next, a catalyst (6) was prepared in the same manner except that the dispersion of alloy fine particles (2) was used.
Treatment of nitrate nitrogen-containing water In Example 1, the nitrate nitrogen-containing water was treated under the same conditions except that the catalyst (6) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(7)の調製
実施例３において、合金微粒子を構成するパラジウムと銅の重量比が５０／５０となるように硝酸パラジウムおよび硝酸銅を加えた以外は同様にして、濃度１０重量％の合金微粒子(3)の分散液とした。合金微粒子の平均粒子径は５ｎｍであった。
ついで、合金微粒子(3)の分散液を用いた以外は同様にして触媒(7)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(7)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (7) In Example 3, an alloy having a concentration of 10% by weight was prepared in the same manner as in Example 3 except that palladium nitrate and copper nitrate were added so that the weight ratio of palladium to copper constituting the alloy fine particles was 50/50. A dispersion of fine particles (3) was obtained. The average particle size of the alloy fine particles was 5 nm.
Next, a catalyst (7) was prepared in the same manner except that the dispersion of alloy fine particles (3) was used.
Treatment of nitrate nitrogen-containing water The nitrate nitrogen-containing water was treated under the same conditions as in Example 1 except that the catalyst (7) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(8)の調製
純水１００ｇに、合金微粒子を構成するパラジウムと銅の重量比が７０／３０となるように硝酸パラジウム２水和塩７.４ｇ及び硝酸銅３水和塩４.９ｇを溶解した金属塩水溶液に、安定化剤として濃度３０重量％のクエン酸三ナトリウム水溶液２６５ｇと還元剤として濃度２５重量％の硫酸第一鉄水溶液２５８ｇ（硝酸パラジウムと硝酸銅の合計モル数の４倍量のモル数に相当）を加え、窒素雰囲気下で２０時間攪拌して合金微粒子の分散液を得た。合金微粒子の平均粒子径は１０ｎｍであった。
得られた分散液を遠心分離器により水洗して不純物を除去した後、水に分散させ、濃度１０重量％の合金微粒子(4)の分散液を得た。ついで、合金微粒子(4)の分散液を用いた以外は実施例３と同様にして触媒(8)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(8)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (8) In 100 g of pure water, 7.4 g of palladium nitrate dihydrate and 4.9 g of copper nitrate trihydrate were added so that the weight ratio of palladium and copper constituting the alloy fine particles was 70/30. In a dissolved metal salt aqueous solution, 265 g of a trisodium citrate aqueous solution having a concentration of 30% by weight as a stabilizer and 258 g of a ferrous sulfate aqueous solution having a concentration of 25% by weight as a reducing agent (four times the total number of moles of palladium nitrate and copper nitrate) The resulting mixture was stirred under a nitrogen atmosphere for 20 hours to obtain a dispersion of alloy fine particles. The average particle size of the alloy fine particles was 10 nm.
The obtained dispersion was washed with water using a centrifugal separator to remove impurities, and then dispersed in water to obtain a dispersion of alloy fine particles (4) having a concentration of 10% by weight. Next, a catalyst (8) was prepared in the same manner as in Example 3 except that the dispersion liquid of alloy fine particles (4) was used.
Treatment of nitrate nitrogen-containing water The nitrate nitrogen-containing water was treated under the same conditions as in Example 1 except that the catalyst (8) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(9)の調製
純水１００ｇに、合金微粒子を構成するパラジウムと銅と銀の重量比が６３／２７／１０となるように硝酸パラジウム２水和塩７.４ｇ、硝酸銅３水和塩４.９ｇ、硝酸銀１.８ｇを溶解した金属塩水溶液に、安定化剤として濃度３０重量％のクエン酸三ナトリウム水溶液２６５ｇと還元剤として濃度２５重量％の硫酸第一鉄水溶液１２９ｇ（硝酸パラジウムと硝酸銅と硝酸銀の合計モル数の１.９倍量のモル数に相当）を加え、窒素雰囲気下で２０時間攪拌して合金微粒子の分散液を得た。合金微粒子の平均粒子径は５ｎｍであった。
得られた分散液を遠心分離器により水洗して不純物を除去した後、水に分散させ、濃度１０重量％の合金微粒子(5)の分散液を得た。ついで、合金微粒子(5)の分散液を用いた以外は実施例３と同様にして触媒(9)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(9)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (9) In 100 g of pure water, 7.4 g of palladium nitrate dihydrate and copper nitrate trihydrate so that the weight ratio of palladium, copper and silver constituting the fine alloy particles is 63/27/10 In a metal salt aqueous solution in which 4.9 g and silver nitrate 1.8 g are dissolved, 265 g of a trisodium citrate aqueous solution with a concentration of 30% by weight as a stabilizer and 129 g of an aqueous ferrous sulfate solution with a concentration of 25% by weight as a reducing agent (palladium nitrate and Equivalent to the number of moles of 1.9 times the total number of moles of copper nitrate and silver nitrate) and stirred for 20 hours in a nitrogen atmosphere to obtain a dispersion of alloy fine particles. The average particle size of the alloy fine particles was 5 nm.
The obtained dispersion was washed with water using a centrifugal separator to remove impurities, and then dispersed in water to obtain a dispersion of alloy fine particles (5) having a concentration of 10% by weight. Next, a catalyst (9) was prepared in the same manner as in Example 3 except that the dispersion liquid of alloy fine particles (5) was used.
Treatment of nitrate nitrogen-containing water The nitrate nitrogen-containing water was treated under the same conditions as in Example 1 except that the catalyst (9) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(10)の調製
実施例３において、予めカーボンブラック（ケッチェンブラックインターナショナル（株）製：ケッチェンブラックＥＣ６００ＪＤ、平均粒子径３１ｎｍ、比表面積１２８０ｍ2／ｇ、結晶子径３．１ｎｍ）を硝酸に分散させ６０℃で１２時間攪拌した後、遠心分離器により水洗し、乾燥して親水性化したカーボンブラック（平均粒子径３１ｎｍ、比表面積１２５０ｍ2／ｇ、結晶子径３．０ｎｍ）を結晶性炭素化合物として用いた以外は同様にして触媒(10)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(10)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (10) In Example 3, carbon black (manufactured by Ketjen Black International Co., Ltd .: Ketjen Black EC600JD, average particle size 31 nm, specific surface area 1280 m 2 / g, crystallite size 3.1 nm) After stirring at 60 ° C. for 12 hours, the mixture was washed with water using a centrifugal separator and dried to make it hydrophilic (average particle size 31 nm, specific surface area 1250 m 2 / g, crystallite size 3.0 nm). A catalyst (10) was prepared in the same manner except that it was used as a functional carbon compound.
Treatment of nitrate nitrogen-containing water The nitrate nitrogen-containing water was treated under the same conditions as in Example 1 except that the catalyst (10) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
硝酸性窒素含有水の処理
実施例３において、水槽にバブリング管（内径０．２ｍｍ）１０本を導入して、水素の流量０.４８Ｌ/ｍｉｎで吹き込んだ以外は同様にして硝酸性窒素含有水の処理を実施した。このときに発生した水素ガスの気泡の大きさは、０．２ｍｍ以上であった。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Treatment of nitrate nitrogen-containing water In the same manner as in Example 3, except that 10 bubbling tubes (inner diameter 0.2 mm) were introduced into the water tank and blown at a hydrogen flow rate of 0.48 L / min. The process of was carried out. The size of the hydrogen gas bubbles generated at this time was 0.2 mm or more. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(R1)の調製
実施例１において、カーボンブラックの代わりに活性炭（和光純薬工業（株）製：活性炭素粉末、平均粒子径５０μｍ、比表面積１１５５ｍ2／ｇ、結晶子径２ｎｍ未満）を用いた以外は同様にして触媒(R1)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(R1)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (R1) In Example 1, instead of carbon black, activated carbon (manufactured by Wako Pure Chemical Industries, Ltd .: activated carbon powder, average particle size 50 μm, specific surface area 1155 m 2 / g, crystallite size less than 2 nm) A catalyst (R1) was prepared in the same manner except that it was used.
Treatment of nitrate nitrogen-containing water In Example 1, the nitrate nitrogen-containing water was treated under the same conditions except that the catalyst (R1) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
硝酸性窒素含有水の処理
実施例１１において、比較例１と同様にして調製した触媒(R1)を用いた以外は同様にして硝酸性窒素含有水の処理を実施した。このときに発生した水素ガスの気泡の大きさは、０．２ｍｍ以上であった。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Treatment of nitrate nitrogen-containing water In Example 11, treatment of nitrate nitrogen-containing water was carried out in the same manner except that the catalyst (R1) prepared in the same manner as in Comparative Example 1 was used. The size of the hydrogen gas bubbles generated at this time was 0.2 mm or more. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
触媒(R2)の調製
純水１００ｇに、金属換算で濃度が１０重量％となり、合金微粒子を構成する銅とパラジウムの重量比が７０／３０となるように硝酸銅および硝酸パラジウムを加え、これに、無定形炭素微粒子（御国色素（株）製：平均粒子径１０９ｎｍ）１９０ｇを加えて１時間撹拌した。次いで、凍結乾燥した後、Ｈ2−Ｎ2混合ガス雰囲気下、２５０℃で２時間加熱処理して触媒(R2)を調製した。
硝酸性窒素含有水の処理
実施例１において、触媒(R2)を用いた以外は同様の条件で硝酸性窒素含有水の処理を実施した。これらの処理の結果および撥水浮遊性の評価結果を表１と表２に示した。
Preparation of catalyst (R2) To 100 g of pure water, copper nitrate and palladium nitrate were added so that the concentration in terms of metal would be 10% by weight and the weight ratio of copper and palladium constituting the alloy fine particles would be 70/30. Then, 190 g of amorphous carbon fine particles (manufactured by Mikuni Dyeing Co., Ltd .: average particle size 109 nm) were added and stirred for 1 hour. Next, after lyophilization, a catalyst (R2) was prepared by heat treatment at 250 ° C. for 2 hours in an H 2 —N 2 mixed gas atmosphere.
Treatment of nitrate nitrogen-containing water In Example 1, the nitrate nitrogen-containing water was treated under the same conditions except that the catalyst (R2) was used. The results of these treatments and the evaluation results of water repellency floatability are shown in Tables 1 and 2.
Claims (9)
The method for treating nitrate-containing water according to any one of claims 1 to 8, wherein the reducing gas is ultrafine bubble hydrogen gas having an average diameter of 0.1 mm or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005203125A JP4649281B2 (en) | 2005-07-12 | 2005-07-12 | Treatment method for nitrate-containing water |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005203125A JP4649281B2 (en) | 2005-07-12 | 2005-07-12 | Treatment method for nitrate-containing water |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2007021289A true JP2007021289A (en) | 2007-02-01 |
| JP4649281B2 JP4649281B2 (en) | 2011-03-09 |
Family
ID=37782744
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005203125A Active JP4649281B2 (en) | 2005-07-12 | 2005-07-12 | Treatment method for nitrate-containing water |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4649281B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011025169A (en) * | 2009-07-27 | 2011-02-10 | Japan Atomic Energy Agency | Catalyst for reductive decomposition of nitrate ion |
| WO2011027864A1 (en) * | 2009-09-04 | 2011-03-10 | 国立大学法人北海道大学 | Photoreduction catalyst, method for synthesizing ammonia using same, and method for decreasing nitrogen oxide in water using same |
| JP2011088077A (en) * | 2009-10-22 | 2011-05-06 | Jfe Mineral Co Ltd | Clarifying material for organic halogen compound and clarification method using clarifying material, recycling method of the clarifying material |
| CN102458652A (en) * | 2009-05-05 | 2012-05-16 | 技术研究及发展基金有限公司 | Activated carbon cloth-supported bimetallic pd-cu catalysts for nitrate removal from water |
| JP2015192935A (en) * | 2014-03-31 | 2015-11-05 | 日揮触媒化成株式会社 | Metal fine particle-carried catalyst, production method thereof and method of treating water containing nitrate nitrogen using the same |
| CN108499567A (en) * | 2018-04-04 | 2018-09-07 | 中国科学技术大学 | The restoring method of nitrate under a kind of normal temperature and pressure |
| JP2019178386A (en) * | 2018-03-30 | 2019-10-17 | 日揮触媒化成株式会社 | Alloy particle dispersion liquid and method for producing the same |
| WO2023238495A1 (en) * | 2022-06-08 | 2023-12-14 | デンカ株式会社 | Slurry, method for producing electrodes, and method for producing batteries |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108993491B (en) * | 2018-08-16 | 2021-04-06 | 南京工业大学 | Activated persulfate catalyst prepared from modified carbon nano tube, and preparation and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02111495A (en) * | 1988-09-10 | 1990-04-24 | Gutec G Zur Entwickl Von Umweltschutztechnol Mbh | Method for continuously removing or reducing nitrite and/or nitrate from water containing nitrite and/or nitrate |
| JP2001000866A (en) * | 1999-06-22 | 2001-01-09 | Asahi Chem Ind Co Ltd | Water treating catalyst composition and water treatment using the catalyst |
| JP2004097893A (en) * | 2002-09-06 | 2004-04-02 | Catalysts & Chem Ind Co Ltd | Catalyst for water treatment and water treatment method |
-
2005
- 2005-07-12 JP JP2005203125A patent/JP4649281B2/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02111495A (en) * | 1988-09-10 | 1990-04-24 | Gutec G Zur Entwickl Von Umweltschutztechnol Mbh | Method for continuously removing or reducing nitrite and/or nitrate from water containing nitrite and/or nitrate |
| JP2001000866A (en) * | 1999-06-22 | 2001-01-09 | Asahi Chem Ind Co Ltd | Water treating catalyst composition and water treatment using the catalyst |
| JP2004097893A (en) * | 2002-09-06 | 2004-04-02 | Catalysts & Chem Ind Co Ltd | Catalyst for water treatment and water treatment method |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102458652A (en) * | 2009-05-05 | 2012-05-16 | 技术研究及发展基金有限公司 | Activated carbon cloth-supported bimetallic pd-cu catalysts for nitrate removal from water |
| JP2011025169A (en) * | 2009-07-27 | 2011-02-10 | Japan Atomic Energy Agency | Catalyst for reductive decomposition of nitrate ion |
| WO2011027864A1 (en) * | 2009-09-04 | 2011-03-10 | 国立大学法人北海道大学 | Photoreduction catalyst, method for synthesizing ammonia using same, and method for decreasing nitrogen oxide in water using same |
| US8986514B2 (en) | 2009-09-04 | 2015-03-24 | National University Corporation Hokkaido University | Photoreduction catalyst, and method for synthesizing ammonia and method for decreasing nitrogen oxides in water using the same |
| JP2011088077A (en) * | 2009-10-22 | 2011-05-06 | Jfe Mineral Co Ltd | Clarifying material for organic halogen compound and clarification method using clarifying material, recycling method of the clarifying material |
| JP2015192935A (en) * | 2014-03-31 | 2015-11-05 | 日揮触媒化成株式会社 | Metal fine particle-carried catalyst, production method thereof and method of treating water containing nitrate nitrogen using the same |
| JP2019178386A (en) * | 2018-03-30 | 2019-10-17 | 日揮触媒化成株式会社 | Alloy particle dispersion liquid and method for producing the same |
| JP7014664B2 (en) | 2018-03-30 | 2022-02-01 | 日揮触媒化成株式会社 | Alloy particle dispersion and its manufacturing method |
| CN108499567A (en) * | 2018-04-04 | 2018-09-07 | 中国科学技术大学 | The restoring method of nitrate under a kind of normal temperature and pressure |
| WO2023238495A1 (en) * | 2022-06-08 | 2023-12-14 | デンカ株式会社 | Slurry, method for producing electrodes, and method for producing batteries |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4649281B2 (en) | 2011-03-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4649281B2 (en) | Treatment method for nitrate-containing water | |
| Xu et al. | Electrocatalytic reduction of nitrate–a step towards a sustainable nitrogen cycle | |
| US9259724B2 (en) | Supported bimetallic nanocomposite catalyst and the preparation method thereof | |
| JP5499753B2 (en) | Water treatment method and apparatus | |
| JPS6111130A (en) | Novel minute aggregate of metal being not noble metal and its production | |
| WO1986006418A1 (en) | Method of dissolving and recovering noble metals | |
| JP2007007541A (en) | Method for treating nitrate nitrogen-containing water | |
| Yang et al. | Opportunities and challenges in aqueous nitrate and nitrite reduction beyond electrocatalysis | |
| JP4111768B2 (en) | Water treatment catalyst and water treatment method | |
| KR101190283B1 (en) | Cu-promoter and pd-noble metal doping nzvi bimetallic catalyst and method of manufacturing the same | |
| CN114262034A (en) | Method for separating rubidium from salt lake brine by using polyvinyl alcohol/chitosan/graphene/nickel copper hexacyanide complex | |
| KR101404597B1 (en) | Nitrate reduction by maghemite supported Cu-Pd bimetallic catalyst | |
| JP5320723B2 (en) | Ultrapure water manufacturing method and apparatus, and electronic component member cleaning method and apparatus | |
| JP2006289248A (en) | Material for removing nitrogen oxide | |
| JP2004097893A (en) | Catalyst for water treatment and water treatment method | |
| CN105642302A (en) | Copper bismuth catalyst for synthesis of 1, 4-butynediol and preparation method thereof | |
| JP4707382B2 (en) | Nitrate nitrogen-containing water treatment catalyst and method for producing the same | |
| CN114917930B (en) | Copper-palladium metal loaded mesoporous carbon coated carbon nanotube one-dimensional nanofiber material and preparation method thereof | |
| JP4439872B2 (en) | Method for producing zeolite catalyst for water treatment | |
| JP4619758B2 (en) | Zeolite catalyst for water treatment | |
| JP5854163B2 (en) | Ultrapure water production method and ultrapure water production facility | |
| JP2012050952A (en) | Method of regenerating denitration waste catalyst | |
| JP2010058008A (en) | Adsorbent | |
| Sarno et al. | Pt/Pd-Fe3O4 nanoparticles for removal of humic acids and Cr (VI) | |
| JP2001000866A (en) | Water treating catalyst composition and water treatment using the catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080701 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20101125 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20101207 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20101213 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131217 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4649281 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |