CN115403135A - Flexible electrode assembly, anaerobic biological denitrification system and application - Google Patents
Flexible electrode assembly, anaerobic biological denitrification system and application Download PDFInfo
- Publication number
- CN115403135A CN115403135A CN202211075369.XA CN202211075369A CN115403135A CN 115403135 A CN115403135 A CN 115403135A CN 202211075369 A CN202211075369 A CN 202211075369A CN 115403135 A CN115403135 A CN 115403135A
- Authority
- CN
- China
- Prior art keywords
- conductive
- flexible
- conductive fiber
- electrode
- anaerobic
- 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
- 239000000835 fiber Substances 0.000 claims abstract description 130
- 229920000049 Carbon (fiber) Polymers 0.000 claims abstract description 66
- 239000004917 carbon fiber Substances 0.000 claims abstract description 57
- 239000001257 hydrogen Substances 0.000 claims abstract description 55
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 55
- 229910052751 metal Inorganic materials 0.000 claims abstract description 53
- 239000002184 metal Substances 0.000 claims abstract description 52
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 50
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 47
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 45
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 23
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 23
- 230000005684 electric field Effects 0.000 claims abstract description 8
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 69
- 241000894006 Bacteria Species 0.000 claims description 57
- 239000004744 fabric Substances 0.000 claims description 29
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 27
- 238000000034 method Methods 0.000 claims description 26
- 239000004743 Polypropylene Substances 0.000 claims description 23
- -1 polypropylene Polymers 0.000 claims description 22
- 229920001155 polypropylene Polymers 0.000 claims description 20
- 230000008569 process Effects 0.000 claims description 19
- 229910001220 stainless steel Inorganic materials 0.000 claims description 16
- 239000010935 stainless steel Substances 0.000 claims description 16
- 230000000712 assembly Effects 0.000 claims description 11
- 238000000429 assembly Methods 0.000 claims description 11
- 238000009941 weaving Methods 0.000 claims description 11
- 229920000877 Melamine resin Polymers 0.000 claims description 9
- 229920000297 Rayon Polymers 0.000 claims description 9
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 9
- 239000004745 nonwoven fabric Substances 0.000 claims description 8
- 229920000388 Polyphosphate Polymers 0.000 claims description 7
- 230000004913 activation Effects 0.000 claims description 7
- 239000001205 polyphosphate Substances 0.000 claims description 7
- 235000011176 polyphosphates Nutrition 0.000 claims description 7
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 claims description 6
- 239000001632 sodium acetate Substances 0.000 claims description 6
- 235000017281 sodium acetate Nutrition 0.000 claims description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 4
- 238000007598 dipping method Methods 0.000 claims description 4
- 150000002431 hydrogen Chemical class 0.000 claims description 4
- 230000020477 pH reduction Effects 0.000 claims description 4
- 238000005406 washing Methods 0.000 claims description 4
- 238000004065 wastewater treatment Methods 0.000 claims description 4
- 230000007062 hydrolysis Effects 0.000 claims description 3
- 238000006460 hydrolysis reaction Methods 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 230000007935 neutral effect Effects 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 238000009835 boiling Methods 0.000 claims description 2
- 238000010000 carbonizing Methods 0.000 claims description 2
- 239000008367 deionised water Substances 0.000 claims description 2
- 229910021641 deionized water Inorganic materials 0.000 claims description 2
- 238000001035 drying Methods 0.000 claims description 2
- 238000007750 plasma spraying Methods 0.000 claims description 2
- 239000002244 precipitate Substances 0.000 claims description 2
- 238000003825 pressing Methods 0.000 claims description 2
- 230000001681 protective effect Effects 0.000 claims description 2
- 238000005507 spraying Methods 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims 1
- 230000008018 melting Effects 0.000 claims 1
- 239000000203 mixture Substances 0.000 claims 1
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 84
- 230000015556 catabolic process Effects 0.000 description 36
- 238000006731 degradation reaction Methods 0.000 description 36
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 34
- 238000006243 chemical reaction Methods 0.000 description 28
- 230000000694 effects Effects 0.000 description 23
- 244000005700 microbiome Species 0.000 description 21
- 239000002351 wastewater Substances 0.000 description 21
- 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 20
- 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 description 19
- 229910052757 nitrogen Inorganic materials 0.000 description 17
- 229910002651 NO3 Inorganic materials 0.000 description 16
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 16
- 230000001651 autotrophic effect Effects 0.000 description 14
- 239000010865 sewage Substances 0.000 description 14
- 239000010802 sludge Substances 0.000 description 13
- 239000000126 substance Substances 0.000 description 13
- 239000012528 membrane Substances 0.000 description 10
- 238000007254 oxidation reaction Methods 0.000 description 10
- 238000000926 separation method Methods 0.000 description 10
- 238000012360 testing method Methods 0.000 description 10
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 9
- 230000000813 microbial effect Effects 0.000 description 9
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 8
- 238000010521 absorption reaction Methods 0.000 description 8
- 239000003153 chemical reaction reagent Substances 0.000 description 8
- 239000000758 substrate Substances 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 239000003344 environmental pollutant Substances 0.000 description 7
- 231100000719 pollutant Toxicity 0.000 description 7
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 230000007797 corrosion Effects 0.000 description 6
- 238000005260 corrosion Methods 0.000 description 6
- 239000003014 ion exchange membrane Substances 0.000 description 6
- 230000009286 beneficial effect Effects 0.000 description 5
- 238000003763 carbonization Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- 230000009471 action Effects 0.000 description 4
- 150000001413 amino acids Chemical class 0.000 description 4
- 229910021529 ammonia Inorganic materials 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 238000012258 culturing Methods 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- 230000027756 respiratory electron transport chain Effects 0.000 description 4
- 239000011734 sodium Substances 0.000 description 4
- 230000003595 spectral effect Effects 0.000 description 4
- 238000002798 spectrophotometry method Methods 0.000 description 4
- 238000000870 ultraviolet spectroscopy Methods 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 3
- 108010052285 Membrane Proteins Proteins 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- CKUAXEQHGKSLHN-UHFFFAOYSA-N [C].[N] Chemical compound [C].[N] CKUAXEQHGKSLHN-UHFFFAOYSA-N 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 230000000593 degrading effect Effects 0.000 description 3
- 229910001873 dinitrogen Inorganic materials 0.000 description 3
- 239000003063 flame retardant Substances 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 239000008103 glucose Substances 0.000 description 3
- 239000013067 intermediate product Substances 0.000 description 3
- 238000002955 isolation Methods 0.000 description 3
- 239000003446 ligand Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000006396 nitration reaction Methods 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 230000009057 passive transport Effects 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 239000006228 supernatant Substances 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 2
- 241000588986 Alcaligenes Species 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 241000589565 Flavobacterium Species 0.000 description 2
- 206010021143 Hypoxia Diseases 0.000 description 2
- 102000018697 Membrane Proteins Human genes 0.000 description 2
- 241000589516 Pseudomonas Species 0.000 description 2
- 230000010757 Reduction Activity Effects 0.000 description 2
- 239000000370 acceptor Substances 0.000 description 2
- 230000009056 active transport Effects 0.000 description 2
- 238000005273 aeration Methods 0.000 description 2
- 241001148470 aerobic bacillus Species 0.000 description 2
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 2
- 230000001580 bacterial effect Effects 0.000 description 2
- 230000032770 biofilm formation Effects 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 230000002503 metabolic effect Effects 0.000 description 2
- 150000002823 nitrates Chemical class 0.000 description 2
- 230000001546 nitrifying effect Effects 0.000 description 2
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 2
- 235000015097 nutrients Nutrition 0.000 description 2
- 150000002897 organic nitrogen compounds Chemical class 0.000 description 2
- 238000010525 oxidative degradation reaction Methods 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000007774 positive electrode material Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- WHBHBVVOGNECLV-OBQKJFGGSA-N 11-deoxycortisol Chemical compound O=C1CC[C@]2(C)[C@H]3CC[C@](C)([C@@](CC4)(O)C(=O)CO)[C@@H]4[C@@H]3CCC2=C1 WHBHBVVOGNECLV-OBQKJFGGSA-N 0.000 description 1
- 241000590020 Achromobacter Species 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 241000193830 Bacillus <bacterium> Species 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 description 1
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 description 1
- 241000192041 Micrococcus Species 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 241000108664 Nitrobacteria Species 0.000 description 1
- 241001453382 Nitrosomonadales Species 0.000 description 1
- 241000187654 Nocardia Species 0.000 description 1
- 241001057811 Paracoccus <mealybug> Species 0.000 description 1
- 241000589597 Paracoccus denitrificans Species 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 241000588769 Proteus <enterobacteria> Species 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 241000605118 Thiobacillus Species 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000004103 aerobic respiration Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000003851 biochemical process Effects 0.000 description 1
- 238000010170 biological method Methods 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000005695 dehalogenation reaction Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000004746 geotextile Substances 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 150000002391 heterocyclic compounds Chemical class 0.000 description 1
- 231100000086 high toxicity Toxicity 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 230000007954 hypoxia Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000013335 mesoporous material Substances 0.000 description 1
- 230000037353 metabolic pathway Effects 0.000 description 1
- 230000004060 metabolic process Effects 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 125000000896 monocarboxylic acid group Chemical group 0.000 description 1
- 239000007773 negative electrode material Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 150000002828 nitro derivatives Chemical class 0.000 description 1
- 238000007034 nitrosation reaction Methods 0.000 description 1
- 125000001477 organic nitrogen group Chemical group 0.000 description 1
- 230000037361 pathway Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 239000002957 persistent organic pollutant Substances 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000012163 sequencing technique Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000004936 stimulating effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Images
Classifications
-
- 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
- C02F3/005—Combined electrochemical biological processes
-
- 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
- C02F3/30—Aerobic and anaerobic processes
- C02F3/302—Nitrification and denitrification treatment
- C02F3/303—Nitrification and denitrification treatment characterised by the nitrification
-
- 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
- C02F3/30—Aerobic and anaerobic processes
- C02F3/302—Nitrification and denitrification treatment
- C02F3/305—Nitrification and denitrification treatment characterised by the denitrification
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Organic Chemistry (AREA)
- Water Supply & Treatment (AREA)
- Environmental & Geological Engineering (AREA)
- Engineering & Computer Science (AREA)
- Biodiversity & Conservation Biology (AREA)
- Microbiology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Molecular Biology (AREA)
- General Chemical & Material Sciences (AREA)
- Electrochemistry (AREA)
- Health & Medical Sciences (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
Abstract
The invention provides a flexible electrode assembly, which comprises a flexible insulating framework, and a conductive fiber positive electrode and a conductive fiber negative electrode which are positioned on two sides of the framework and are not communicated, wherein the conductive fiber positive electrode and the conductive fiber negative electrode are formed by flexible high-conductivity carbon fibers or activated carbon fibers coated with conductive metal layers, and metal current guide nets are clamped between the conductive fiber positive electrode and the conductive fiber negative electrode and the flexible insulating framework. The invention also provides an anaerobic electric biological denitrification system and application, comprising an anaerobic electric biological denitrification reactor, wherein the flexible electrode assembly can be arranged in a container or a water tank, the bottom of the anaerobic electric biological denitrification reactor is provided with a stirrer, the positive electrode and the negative electrode of the conductive fiber are respectively connected with a power supply through metal diversion nets, a biomembrane electrode is formed by acclimation of an external electric field, the negative electrode of the conductive fiber is enabled to separate hydrogen, and carbon dioxide is separated out from the positive electrode to be used as denitrification energy. The flexible electrode assembly improves the conductivity of the electrode, is applied to an anaerobic electro-biological denitrification system, and improves the denitrification efficiency.
Description
Technical Field
The invention belongs to the technical field of water treatment, and particularly relates to a flexible electrode assembly and an anaerobic electro-biological denitrification system used in a municipal sewage treatment process and application thereof.
Background
In recent years, with the aggravation of water body pollution, more and more nitrogen elements are discharged into the water body, the index of individual areas in China is as high as 3Omg/L and even higher, when the discharge amount of ammonia nitrogen in the water body exceeds the self-purification capacity, the aggravation of the water body pollution is caused, the high ammonia nitrogen content in the water body seriously influences the human health, meanwhile, the normal growth of aquatic organisms is influenced due to the overhigh ammonia nitrogen content in the water, and therefore, the denitrification and dephosphorization of the sewage are of great importance.
The ammonia nitrogen-containing wastewater has the characteristics of wide source, high toxicity and complex components, has become a hotspot of research of professional experts, and develops a plurality of treatment technologies aiming at low or high concentration ammonia nitrogen wastewater, wherein the treatment means of the ammonia nitrogen wastewater comprises physical treatment, chemical treatment, biological treatment, some comprehensive treatment and the like. The traditional biological denitrification process is developed by slightly improving the basic principle of the purification effect of microorganisms on ammonia nitrogen in the nature, has some defects when being applied to sewage treatment, such as high treatment cost, high energy consumption and the like, and continuously develops a new denitrification process through the efforts of technical personnel in the field, wherein the processes such as synchronous nitrification and denitrification, short-cut nitrification and denitrification, anaerobic ammonia oxidation and the like are novel biological denitrification processes. Aiming at treating high ammonia nitrogen wastewater, no matter which biological denitrification technology is combined, the defects of slow reaction and long time consumption can not be overcome, at present, the latest research is to combine an electric auxiliary method and a microbial method to form a new electric auxiliary microbial system and degrade ammonia nitrogen through organic matters, so that the reaction time is shortened, the reaction rate is improved, the organic matters originally contained in sewage can be reasonably utilized to degrade ammonia nitrogen, and the defect of ammonia nitrogen treatment by the traditional anaerobic biological method is overcome.
An Electric Assisted Microbial System (EAMS) is called an electric biological System for short, and is a special Microbial Electrolysis Cell System (MEC). In an electrobiological system, microorganisms with electrocatalytic activity adhere to electrode materials under the action of an applied voltage to form a biofilm electrode, and an anode and a cathode in the system respectively undergo oxidation and reduction reactions. The electric bioreactor is mainly divided into a single-chamber, double-chamber and multi-chamber reactor. The difference between them is mainly whether there is an ion exchange membrane. The single-chamber reactor has two stages of cathode and anode in one reactor and no ion exchange membrane, the double-chamber reactor has two stages of cathode and anode in two different reactors and one ion exchange membrane, and the multi-chamber reactor consists of several cathodes and anodes with one ion exchange membrane between each two adjacent cathode chambers and anode chambers. Because the price of the ion exchange membrane is high, the manufacturing cost of the single-chamber reactor is greatly reduced compared with that of the other two reactors, and because the anode and the cathode are in one reactor, the intermediate product generated after the cathode reaction of the pollutant can move to the anode to generate oxidation reaction to be decomposed, thereby forming a cycle of the oxidation-reduction reaction.
For an electric auxiliary microbial system, a metal plate or a graphite plate and the like are mostly used as an electrode plate for research, but the metal plate or the graphite plate and an ion exchange membrane are expensive and complicated to install, and the problems of small specific surface area of materials, slow microbial biofilm formation and the like are main reasons for causing difficulty in large-scale application.
Therefore, there is a need to address the above-mentioned deficiencies of the prior art.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and firstly provides a flexible electrode assembly used in the urban sewage treatment process, which improves the efficiency of removing industrial ammonia nitrogen in sewage, has low cost and can be produced and applied in a large scale.
The invention provides a flexible electrode assembly, which comprises a flexible insulating framework, and a conductive fiber positive electrode (anode) and a conductive fiber negative electrode (cathode) which are respectively attached to two sides of the flexible insulating framework and are not conducted, wherein the conductive fiber positive electrode and the conductive fiber negative electrode are formed by flexible high-conductivity carbon fibers or activated carbon fibers coated with conductive metal layers, metal current-conducting nets are respectively clamped between the conductive fiber positive electrode and the conductive fiber negative electrode and the flexible insulating framework, and the outer sides of the conductive fiber positive electrode and the conductive fiber negative electrode are respectively provided with a compaction fixing net for connecting the flexible insulating framework, the conductive fiber positive electrode, the conductive fiber negative electrode and the metal current-conducting nets into a whole.
In the flexible electrode assembly, the electrode is formed by flexible high-conductivity carbon fibers or activated carbon fibers sprayed with a conductive metal layer and is combined with the metal current guiding net, the resistance of the metal current guiding net is 0 ohm, so that the electrode current can longitudinally accelerate to pass, and meanwhile, the transverse conductivity of the metal current guiding net is combined by utilizing the characteristics of excellent comprehensive performance, high conductivity and the like of the flexible high-conductivity carbon fibers, or the surface of the activated carbon fibers is sprayed with the conductive metal layer to reduce the internal resistance of the activated carbon fibers so as to strengthen the transverse conductivity of the electrode and the metal current guiding net; the electronic transfer ensures that some relatively large polar or charged molecules, such as glucose, amino acid, ions and other substances cannot freely pass through the membrane, the transportation of the substances needs the mediation of membrane protein to carry out passive transfer, and the energy required by the electronic transfer drives the separation of the receptor and the ligand, so that the active transfer mode for completing the recycling of the receptor is more superior to the passive transfer mode, and the rapid formation of the biomembrane electrode is promoted; microorganisms are attached to an electrode material and domesticated through an external electric field, a biomembrane electrode can be quickly formed, so that a negative electrode of conductive fibers can perform hydrogen evolution reaction, a positive electrode of the conductive fibers can perform carbon dioxide evolution, bacteria can utilize active hydrogen as energy and assimilate carbon dioxide, when the conductive fiber is applied to an anaerobic denitrification system, the negative hydrogen evolution reaction has two forms of hydrogen products, namely active hydrogen and hydrogen molecules, the active hydrogen can be utilized by denitrifying bacteria firstly, and the autotrophic denitrifying bacteria convert nitrate into nitrogen through denitrification by utilizing the active hydrogen of the negative electrode, so that ammonia nitrogen and nitrate nitrogen are removed.
The invention also provides an anaerobic electro-biological denitrification system, which comprises an anaerobic electro-biological denitrification reactor, wherein the anaerobic electro-biological denitrification reactor is characterized in that the flexible electrode assembly is arranged in a container or a water tank, a stirrer is arranged at the bottom of the container or the water tank, the conductive fiber positive electrode and the conductive fiber negative electrode in the flexible electrode assembly are respectively connected with a power supply through a metal diversion net communicated with the flexible electrode assembly, denitrifying bacteria are domesticated through an external electric field to form a biomembrane electrode, the conductive fiber negative electrode is enabled to separate hydrogen, the conductive fiber positive electrode separates out carbon dioxide, and active hydrogen and carbon dioxide are used as denitrification energy sources to be applied to denitrification of an anaerobic denitrification system.
When the anaerobic electro-biological denitrification system is used for sewage treatment, the degradation rate of nitrite nitrogen in water is very high, the nitrite nitrogen can be completely degraded within 5 hours, the degradation rate of ammonia nitrogen in water is over 85 percent within 12 hours, and the degradation rate of nitrate nitrogen reaches 95 percent after 12 hours after acetic acid or sodium acetate is added as a reaction substrate.
The anaerobic electro-biological denitrification system has low external voltage, effectively reduces the cost of industrial implementation, solves the problems of difficult scale engineering application, high device manufacturing cost and the like of the traditional electrodes adopting metal plates, graphite and the like, meets the requirements of the current industry and has very wide application prospect.
The invention also provides the application of the flexible electrode assembly in the wastewater treatment process, the flexible electrode assembly can be applied to the hydrolysis acidification process before anaerobic or aerobic treatment, and can hydrolyze the ring-chain or long-chain organic matters which are not easy to biodegrade into short-chain low-molecular organic matters which are easy to degrade, thereby effectively improving the biodegradability of sewage and improving the denitrification efficiency.
Drawings
FIG. 1A is a schematic view of a flexible electrode assembly of the present invention;
FIG. 1B is a schematic diagram of the arrangement of the components of FIG. 1;
FIG. 2 is a diagram of an embodiment of a flexible highly conductive carbon fiber weave structure for a conductive fiber positive electrode in a flexible electrode assembly of the present invention;
FIG. 3 is a schematic view of the flexible electrode assembly of the present invention after winding;
FIG. 4 is a schematic view of a plurality of flexible electrode assemblies of the present invention in combination;
FIG. 5 is a schematic view of an electric bioreactor assembly of the present invention;
FIG. 6 is a schematic view of an anaerobic electro-biological denitrification system according to the present invention;
FIG. 7 is a diagram illustrating the degradation effect of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the embodiment of the anaerobic electro-biological denitrification system;
FIG. 8 is a diagram showing the degradation effect of two pairs of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the embodiment of the anaerobic electro-biological denitrification system of the present invention;
FIG. 9 is a diagram showing the degradation effect of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the anaerobic electro-biological denitrification system of the third embodiment of the present invention;
FIG. 10 is a diagram illustrating the degradation effect of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the anaerobic electro-biological denitrification system of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Referring to fig. 1A-1B, the flexible electrode assembly 1 provided by the present invention includes at least one flexible insulating skeleton 11, where the flexible insulating skeleton 11 is a substrate of the flexible electrode assembly 1, and may be a corrosion-resistant and flexibly deformable mesh member, and two sides of the flexible insulating skeleton 11 are respectively provided with a non-conductive fiber positive electrode 13 and a conductive fiber negative electrode 14, where the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 may be made of flexible highly conductive carbon fibers or activated carbon fibers sprayed with a conductive metal layer, where the flexible highly conductive carbon fibers are a highly conductive material, and have excellent comprehensive properties, besides having high conductivity, corrosion resistance, wear resistance, high temperature resistance, high strength, light weight, and the like; the conductive metal layer is sprayed on the surface of the activated carbon fiber, so that the internal resistance of the activated carbon fiber can be reduced, and the contact with a wastewater interface and the smoothness of an electronic channel are facilitated. Metal current-conducting nets 12 are respectively clamped between the conductive fiber positive electrodes 13 and the conductive fiber negative electrodes 14 and the flexible insulating framework 11, the metal current-conducting nets 12 can enable electrode current to longitudinally accelerate to pass, the conductive fiber positive electrodes 13 and the conductive fiber negative electrodes 14 adopt flexible high-conductivity carbon fibers or activated carbon fibers sprayed with conductive metal layers to have transverse passing current, when the conductive fiber positive electrodes and the conductive fiber negative electrodes are combined with the metal current-conducting nets 12, the transverse conducting performance of the conductive fiber positive electrodes 13 and the conductive fiber negative electrodes 14 can be further improved, and certain relatively large polar or charged molecules, such as glucose, amino acid, ions and the like, cannot freely pass through the membrane through electron transfer. The transportation of the substances needs the mediation of membrane proteins for passive transport, and the energy required by electron transfer drives the separation of the receptor and the ligand, so that the active transport mode for completing the recycling of the receptor is more superior to the passive transport mode, and the rapid formation of the biomembrane electrode is promoted. The outer sides of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 are provided with a compression fixing net 15, the outer surface of the compression fixing net 15 can be provided with a plurality of stainless steel fixing strips 16, the arranged conductive fiber positive electrode 13, the metal current guiding net 12, the flexible insulating framework 11 and the conductive fiber negative electrode 14 can be mutually compressed and attached, and all the components can be connected and fixed into a whole through a fixing piece 17 to form the integral flexible electrode assembly 1.
As a preferred mode of the flexible electrode assembly 1 of the present invention, the flexible insulating framework 11 is a geotextile mat made of melt-blown PP material, and the thickness is 1.6-2.5 cm. The geotechnical mat is a member formed by multilayer lapping of PP random filaments, has a large number of irregular transverse and longitudinal mesh passages, has a larger specific surface area compared with a regular round hole or honeycomb Kong Wangzhuang member in the prior art, is very beneficial to microorganism film hanging, resists corrosion and high pressure, has large hole opening density, and has functions of all-round water passing and horizontal drainage.
As a preferable mode of the flexible electrode assembly 1 of the present invention, the metal current guiding net 12 is woven by stainless steel 316S wires with a monofilament diameter of 0.1-2mm, and is used for increasing the longitudinal and transverse conductivity of the electrode, and the mesh size of the metal current guiding net 12 is 2-5mm, which is beneficial to contact with a wastewater interface and smoothness of an electronic channel. It will be appreciated that stainless steel is a corrosion resistant conductive material, and other corrosion resistant conductive materials may be selected to ensure the useful life of the flexible electrode assembly.
The flexible high-conductivity carbon fibers have the main functions of transversely receiving current transmitted by the metal current guide net 12, providing a home-keeping place for microorganisms, and domesticating denitrifying bacteria to form a biomembrane electrode under an anaerobic working condition through an external electric field. The flexible high-conductivity carbon fiber is formed by one-time mixed weaving of polypropylene fiber and conductive carbon fiber by a rapier loom; weaving the flexible high-conductivity carbon fiber, twisting polypropylene fiber monofilaments which are arranged in a way of mixing 1K-12K flexible high-conductivity carbon fiber and are 100-300D into warps and wefts, namely mixing one strand of conductive carbon fiber with one strand of polypropylene fiber. The method comprises the steps of mixing 1K-12K electric carbon fibers and 100-300D polypropylene fibers to form a plurality of longitudinally and transversely arranged large units shaped like a Chinese character 'tian', wherein each large unit shaped like a Chinese character 'tian' comprises four small units shaped like a Chinese character 'tian', thick warps and thick wefts, which are formed by mixing conductive carbon fibers and polypropylene fibers, are alternately used as frames for each large unit shaped like a Chinese character 'tian', middle ribs A of the large unit shaped like Chinese character 'tian' adopt middle and thick warps and middle and thick wefts of the conductive carbon fibers and serve as frames for four small units shaped like a Chinese character 'tian', small ribs B in the middle of each small unit shaped like a Chinese character 'tian' adopt conductive carbon fiber warps and wefts, and a plurality of polypropylene fiber monofilaments warps and monofilaments are longitudinally and transversely arranged on two sides of each small rib B shaped like a Chinese character 'tian', so that a curtain type grid cloth is formed.
Fig. 2 is a structural example diagram of weaving of each large "tian" -shaped unit of the flexible high-conductivity carbon fiber. On the rapier loom, each large 'tian' shaped unit is provided with a strand of 12K conductive carbon fiber mixed strand 250D polypropylene fiber as a thick warp 1313 every 5-10 cm from the selvage 133 to the right in sequence, and a strand of 12K conductive carbon fiber mixed strand 250D polypropylene fiber as a thick weft 1323 every 5-10 cm from the top to the bottom in sequence, so as to form a frame. Then, arranging a single-strand 6K conductive carbon fiber medium thick warp yarn 1312 in the middle of each thick warp yarn 1313, arranging a single-strand 6K conductive carbon fiber medium thick weft yarn 1322 in the middle of each thick weft yarn 1323, and crossing to form a large cross-shaped rib A to form a large field-shaped unit; two sides of the thick warp 1312 in the 6K conductive carbon fiber are equidistantly provided with another 3K conductive carbon fiber warp 1311, two sides of the thick weft 1322 in the 6K conductive carbon fiber are equidistantly provided with another 3K conductive carbon fiber weft 1321, and the two warps are crossed to form a cross-shaped rib B, so that four small-shaped units shaped like Chinese character 'tian' are formed; three 100D polypropylene fiber warp 1314 are arranged on two sides of the 3K conductive carbon fiber warp 1311 at equal intervals, and three 100D polypropylene fiber weft 1324 are arranged on two sides of the 3K conductive carbon fiber weft 1321 at equal intervals, so that a plurality of grids are arranged in the middle of each small 'tian' shaped unit. When weaving the warp and weft, respectively and sequentially driving 12K conductive carbon fiber mixed 250D polypropylene fiber warp and weft, single-strand 6K conductive carbon fiber warp and weft, single-strand 3K conductive carbon fiber warp and weft and six strands of 100D polypropylene fiber warp and weft by at least 4 weft feeders to carry out warp and weft weaving, and finally weaving into weaving curtain type grid cloth with 9 warp weaving belts and 8 empty warp and weft weaving transverse nets, wherein the length of the conductive carbon fiber grid cloth is 50-100 meters, the conductive carbon fiber grid cloth is cut into 1-8 meters of weaving square conductive carbon fiber cloth according to the length required by practical application when in use, the resistance of the woven square conductive carbon fiber cloth is detected by a universal meter to be less than 50 ohms, compared with the prior art, the woven square conductive carbon fiber cloth has the advantages of low manufacturing cost, large specific surface area and the like although the resistance is slightly higher than that of a stainless steel perforated plate or a stainless steel net in the prior art, the cost of the woven square conductive carbon fiber cloth is only 20-30 percent of the conductive carbon fiber cloth woven by using all conductive carbon fiber wires, and the woven square conductive carbon fiber cloth can be used as a positive electrode material of the flexible electrode assembly 1.
Furthermore, after the flexible high-conductivity carbon fiber is woven into the grid cloth, the cutter can be used for cutting the middle position of the small cross-shaped rib B in the middle of each small Chinese character tian-shaped unit into a cross-shaped notch, namely, the middle of the conductive carbon fiber warp 1311 and the conductive carbon fiber weft 1321 crossed in the middle of each small Chinese character tian-shaped unit is cut open, the notch position does not damage the frame of the small Chinese character tian-shaped unit, so that each large Chinese character tian-shaped unit forms 4 cross-shaped notches, and the thread end of the cut conductive carbon fiber can float out from the notch and freely extend outwards. Or cutting the polypropylene fiber monofilament warp and weft along the edge of the small cross-shaped rib B of each small field-shaped unit, forming an L-shaped notch at the position of the small cross-shaped rib B, so that 4L-shaped notches are formed in each small field-shaped unit, forming 16L-shaped notches in each large field-shaped unit, keeping the connection of the small cross-shaped ribs B of each small field-shaped unit, and making the cut polypropylene fiber monofilament end float out from the notch and freely stretch outwards. After the flexible high-conductivity carbon fiber mesh cloth is cut, the stretched fiber yarns float in water, so that the membrane hanging amount of microorganisms can be increased, the electron transfer rate of a conductive fiber electrode is improved, certain relatively large polar or charged molecules, such as glucose, amino acid, ions and the like, cannot freely pass through the membrane, the transportation of the substances needs to be passively transported by the mediation of membrane protein, the energy required by the electron transfer drives the receptor to be separated from the ligand, the active transport mode for completing the recycling of the receptor has more superiority than the passive transport mode, the rapid formation of a biomembrane electrode is promoted, and the smooth reaction of the biomembrane is ensured.
The active carbon fiber also has the main function of transversely receiving the current transmitted by the metal diversion net 12, providing a home-keeping place (biofilm formation) for microorganisms, and domesticating denitrifying bacteria to form a biomembrane electrode under an anaerobic working condition through an external electric field. The conductive metal layer of the activated carbon fiber is prepared by dipping activated carbon fiber cloth in melamine polyphosphate with the concentration of 10-15% for 2 hours, and after the melamine polyphosphate plays a role of flame retardance, the conductive metal layer is dipped at 5Kg/cm 2 Under the condition of compressed air, a plasma spraying mode is adopted to melt and spray conductive metal (such as stainless steel 316S wires) on one surface of the activated carbon fiber cloth, and the surface sprayed with the conductive metal layer is opposite to the metal current guiding net 12 and is attached to the metal current guiding net 12. After spraying, the conductive metal permeates one surface of the activated carbon fiber to form a conductive framework network structure, the other surface (the surface without the stainless steel 316S) of the activated carbon fiber cloth still keeps the characteristics of the activated carbon fiber cloth so as to reduce the internal resistance of the contact surface of the metal flow guide net 12 to the maximum extent, thus not only keeping the characteristics of large specific surface area, strong adsorption performance, corrosion resistance, good conductivity and stable electrochemical characteristics of the activated carbon fiber, ensuring that organic matters in water are adsorbed on the surface of the activated carbon fiber, but also ensuring that stainless steel 316S wires are meltedThe activated carbon fiber cloth is sprayed on the surface of the activated carbon fiber cloth and is combined with the metal flow guide net 12, so that the transverse conductivity of the activated carbon fiber electrode can be further enhanced.
The activated carbon fiber cloth is prepared by the following steps:
s1, dipping the adhesive-based non-woven fabric for 2 hours by using melamine polyphosphate with the concentration of 10-15%.
The melamine polyphosphate is a nitrogen-containing flame retardant which is subjected to decomposition reaction when heated, and the nitrogen-containing flame retardant mainly comprises melamine and derivatives thereof and related heterocyclic compounds, and has better properties than halogen-containing flame retardants and red phosphorus. Melamine is very effective in flame retardancy when used with metal oxides, certain organic phosphoric acids or alkali or alkaline earth metal salts. The viscose-based non-woven fabric is impregnated with melamine polyphosphate before carbonization, so that the viscose-based non-woven fabric can be prevented from being burnt and oxidized in the carbonization process.
And (2) pre-oxidizing the viscose at the temperature of 200-250 ℃ for 30-60 min to convert the linear molecular chain of the viscose into a heat-resistant ladder-shaped structure, so that the raw material is ensured not to be oxidized and burnt in the carbonization process, and is not melted and burnt during subsequent high-temperature carbonization so as to keep the fiber state.
S3, carbonizing at 250-350 ℃ for 1-2 h under a protective atmosphere (argon or helium) to fiberize the viscose-based non-woven fabric. The carbonization process controls the temperature rise rate, and basically ensures that the temperature rises from the front to the back, and rises from the front to the back and is fast from the front to the back.
S4, performing pore-forming treatment on the carbonized viscose-based non-woven fabric by using water vapor, (removing impurities in a micropore channel) and then performing activation treatment at the temperature of 900-1000 ℃ for 6-8 h; the viscose-based non-woven fabric fiber is activated at high temperature to form activated carbon fiber, and micropores are distributed on the surface of the fiber, so that the fiber has a large specific surface area and is used for adsorbing pollutants in wastewater.
In the step, the activation temperature is high, which is favorable for improving the specific surface area, but the microporous structure is easy to collapse due to the overhigh temperature; the long activation time is beneficial to complete activation, but the yield of the activated carbon fiber cloth is easily reduced, the pore diameter and pore distribution of the final product need to be controlled necessarily, and the dosage of the activation medium is strictly controlled at different positions of the activation stage.
And S5, washing with 20% sulfuric acid to remove impurities (including dust and harmful metal elements) in the activated carbon fiber cloth, then washing with boiling deionized water to be neutral, and drying in an oven.
The specific surface area of the activated carbon fiber cloth prepared by the method can reach 1590m 2 The mesoporous material has the advantages of low manufacturing cost, large specific surface area and the like, and can be used as a positive electrode material and a negative electrode material of the flexible electrode assembly 1.
Referring to fig. 3, the flexible electrode assembly 1 of the present invention can be wound in a spiral shape, the middle of the flexible electrode assembly is separated by a separation net 2 or a flexible insulation framework 11, a plurality of separation columns 3 can be arranged on the separation net 2, the length of the separation column is 1.6-2.5cm, each layer of flexible electrode assembly 1 can be ensured to keep the same distance, and the non-conductive fiber positive electrode and the conductive fiber negative electrode are respectively connected with the positive electrode outgoing line 4 and the negative electrode outgoing line 5, so as to form a cylindrical-like electric bioreactor assembly composed of single flexible electrode assemblies.
Referring to fig. 4, when the flexible electrode assemblies 1 of the present invention are combined in multiple layers, an insulating separation net 2 may be used to separate each flexible electrode assembly 1, and separation columns 3 are disposed on the separation net 2 to keep the flexible electrode assemblies 1 at the same distance, and the separation net 2 may be replaced by a flexible insulating skeleton 11. In order to ensure that the flexible electrode assemblies 1 still have the bending performance after being combined and connected into a whole, the arrangement positions of the fixing pieces 17 and the isolation columns 3 are staggered. Referring to fig. 5, after a plurality of flexible electrode assemblies 1 are combined, the non-conductive fiber positive electrodes 13 and conductive fiber negative electrodes 14 in the flexible electrode assemblies 1 are respectively connected with the positive electrode lead wires 4 and the negative electrode lead wires 5, so as to form an electric bioreactor assembly consisting of a plurality of flexible electrode assemblies.
Referring to fig. 6, the present invention provides an anaerobic electro-biological denitrification system comprising an anaerobic electro-biological denitrification reactor 6, wherein the anaerobic electro-biological denitrification reactor 6 has a container or a water tank (shown as a container 66), and a flexible electrode assembly 1 is disposed in the container 66 and supported by a mesh supporting plate 61 disposed in the container 66. The conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 in the flexible electrode assembly 1 are respectively connected with a direct current power supply 7 (power supply voltage is 0.3-0.8V) through a positive electrode lead wire 4 and a negative electrode lead wire 5. The bottom of the container 66 is provided with a plug flow type stirrer 62 which is connected with an output shaft of a motor 63 and is driven by the motor 63 to rotate. Sewage to be treated enters from a water inlet 64, the sewage is discharged from a water outlet 67 after reacting for a certain time in an anaerobic state, a plug flow type stirrer 62 is connected with a power supply during the reaction, a motor 63 drives the plug flow type stirrer 62 to intermittently work under the control of a control system, denitrifying bacteria are domesticated by an external electric field to form a biomembrane electrode through a conductive fiber positive electrode 13 and a conductive fiber negative electrode 14 under the anaerobic working condition, the conductive fiber negative electrode 14 is enabled to perform hydrogen evolution reaction, carbon dioxide is separated out from the conductive fiber positive electrode 13, bacteria use hydrogen as energy and assimilate the carbon dioxide, so that the flexible electrode assembly 1 is applied to an anaerobic denitrification system, the cathode hydrogen reaction has two forms of hydrogen products which are respectively active hydrogen and hydrogen molecules, the active hydrogen can be used by the denitrifying bacteria firstly, the autotrophic denitrifying bacteria use the active hydrogen at the cathode to convert nitrate into nitrogen through denitrification, and the aim of high-efficiency denitrification is achieved.
Furthermore, the anaerobic electro-biological denitrification system can also be provided with a dosing port 65 on the water inlet 64, acetic acid or sodium acetate is added as a reaction substrate when sewage enters the reactor, the addition amount is calculated by taking the carbon-nitrogen ratio as 2, the precipitation of negative electrode hydrogen is facilitated, hydrogen bacteria utilize hydrogen as an energy source and assimilate carbon dioxide, so that the activated carbon fiber electrode with enhanced electrical conductivity and the denitrification path of the EAMS system react to form two forms of hydrogen products, namely active hydrogen and hydrogen molecules, the active hydrogen is firstly utilized by denitrifying bacteria, and the autotrophic denitrifying bacteria utilize the active hydrogen and the carbon dioxide generated by the two poles to convert nitrate into nitrogen, thereby achieving the purpose of denitrification.
The traditional biological denitrification system utilizes the principle of natural nitrogen circulation to create an environment suitable for the growth of different microorganism populations in water treatment, improves the biological nitrification and denitrification rate, and achieves the aim of removing nitrogen in wastewater through ammoniation, nitrification and denitrification.
(1) Ammoniation: the organic nitrogen in untreated urban sewage mainly comprises protein, amino acid, urea, amine, cyanide, nitro compound and the like. The organic nitrogen compound is decomposed and converted into ammoniacal nitrogen under the action of aerobic bacteria and ammoniation bacteria.
(2) Nitration reaction: the biological nitrification reaction is to oxidize ammonia nitrogen into nitrite nitrogen and nitrate nitrogen by nitrosobacteria and nitrobacteria, and is completed by a group of autotrophic aerobic microorganisms through two processes: the first step is to convert ammonia nitrogen into nitrite by nitrite bacteria, which is called nitrosation reaction, and the second step is to oxidize nitrite into nitrate by nitrate bacteria.
(3) And (3) denitrification reaction: the biological denitrification reaction is a process of reducing nitrate or nitrite produced during nitrification into gaseous nitrogen or nitrogen oxide in an anoxic state, and is performed by assimilation and catabolism of a group of heterotrophic microorganisms. The dissimilatory action is to reduce nitrite and nitrate into nitrogen gas and nitrogen oxide and other gas substances, mainly nitrogen gas. The assimilation is that the denitrifying bacteria reduce nitrite and nitrate into ammonia nitrogen for new cell synthesis.
Biological denitrification is mainly completed by two processes of nitrification and denitrification. The nitration reaction is completed by autotrophic aerobic microorganisms, and comprises two stages, wherein in the first stage, nitrite bacteria convert ammonia nitrogen into nitrite nitrogen; in the second stage, nitrite nitrogen is further oxidized into nitrate nitrogen by nitrate bacteria. Nitrite and nitrate bacteria are collectively referred to as nitrifying bacteria. Nitrification of obligate aerobic bacteria using inorganic substances such as CO 3 2- 、HCO 3- 、CO 2 Etc. as a carbon source from NH 3 -N and NO 2 Energy is obtained in the oxidation reaction of-N. The denitrification reaction is a biochemical process performed by heterotrophic microorganisms. Its main effect is in hypoxia (DO)<0.3-0.5 mg/L) of nitrite and nitrate produced in the course of nitration are reduced into gaseous nitrogen (N) 2 、N 2 O or NO). During the course of denitrification, nitrate nitrogen acts through the metabolism of denitrifying bacteria, and there are two transformation pathways: one is assimilation denitrification, i.e. cell synthesis, which finally forms organic nitrogen compounds as part of the bacterial cells; the other way is dissimilatory denitrification, i.e. decomposition, with gaseous nitrogen as the final product.
In an anaerobic electro-biological denitrification system, under the condition of oxygen deficiency (DO is less than 0.3-0.5 mg/L), microorganisms play a leading role in degrading ammonia nitrogen, an external voltage plays an auxiliary role, the voltage applied to the whole system is used for stimulating the metabolic activity and the reduction activity of the whole system by electrons generated by an electrode, the electrode is coupled with microbial strains to play a synergistic role in degrading ammonia nitrogen, and the degradation effect of ammonia nitrogen can be greatly improved. When a pure microbial system degrades ammonia nitrogen, electrons required by ammonia nitrogen oxidative degradation mainly come from microbes, and the microbes lack a large number of electron donors, so that the ammonia nitrogen is degraded only in a small amount, and the ammonia nitrogen needs a long time for little degradation; when a simple electrochemical system degrades ammonia nitrogen, a large amount of electron donors can be provided for the oxidative degradation of ammonia nitrogen, so that the ammonia nitrogen can be degraded in a small degree in the system, but the degradation speed is very low, and the main reason of the problem is probably that the ammonia nitrogen is difficult to degrade due to the accumulation of redox intermediate products; when the electric biological system degrades ammonia nitrogen, on one hand, microorganisms are attached to the surface of the electrode to form a biological electrode due to the coupling effect of the microorganisms and the electrode, and after an external voltage is supplied, the negative electrode can provide more electrons under a lower voltage, and the microorganisms can efficiently utilize the electrons generated by the electrode to stimulate the metabolic activity and the reduction activity of the microorganisms, so that the ammonia nitrogen can be better degraded, and on the other hand, part of intermediate products generated by the negative electrode can be degraded due to the reaction of pollutants in the electric biological system at the positive electrode, so that the degradation reaction of the ammonia nitrogen can be carried out more smoothly. The electric biological system is a coupling body of a pure electrochemical system and a microbial system, can embody the advantages of the two systems and avoid the respective disadvantages of the two systems, and can reduce the cost for industrial implementation due to low external voltage, thereby providing a new idea for the treatment of ammonia nitrogen.
The anaerobic electric biological denitrification system of the invention is to reform the traditional hydrolytic acidification system or anaerobic system through a flexible electrode assembly, and by utilizing the electrochemical principle and the biological principle, the flexible electrode provides microorganisms with huge specific surface to pass through an at-home place, and the biological membrane electrode is formed by domesticating denitrifying bacteria with an external electric field, and active hydrogen generated by a conductive fiber electrode is efficiently utilized by the denitrifying bacteria, thereby being beneficial to biological denitrification.
The principle fully combines an electrochemical method and a biological membrane method, and comprises the electrochemical principle and the biological principle.
(1) Electrochemical principle: in each electrode assembly, a certain current is applied, the negative electrode is used for hydrogen evolution, the positive electrode is used for carbon dioxide evolution, bacteria use active hydrogen as energy and assimilate carbon dioxide, the electrode assembly is applied to an anaerobic denitrification system, and autotrophic denitrifying bacteria use active hydrogen and carbon dioxide generated by the two electrodes to convert nitrate into nitrogen through the denitrifying bacteria.
Industrial wastewater treatment stations, waterworks and municipal sewage treatment plants generally contain:
H + ,OH - ,Cl - ,Ca 2+ ,Mg 2+ ,Na + ,NO 3- and (3) plasma.
The possible reaction on the negative electrode is:
(Fe)：Fe – 2e→Fe 2+ E0(Fe 2+ /Fe)＝–0.44V
Ca 2+ +2e＝Ca e＝-2.868V
Mg 2+ +2e＝Mg e＝-2.372V
Na + +e＝Na e＝-2.71V
2H + +2e＝H 2 e＝0V
NO 3- +2H + +e＝NO 2 +H 2 O e＝0.799V
NO 3- +4H + +2e＝NO+2H 2 O e＝0.957V
the possible reaction on the positive electrode:
(C)：2H + +2e→H 2 E0(H + +/H 2 )＝0V
2Cl - ＝Cl 2 +2e e＝1.35V
C+2H 2 O＝CO 2 +4H + +4e e＝0.207V
4OH - ＝O 2 +2H 2 O+4e e＝0.401V
what kind of product is precipitated on the electrode first depends on various factors, such as the concentration of the ion, overpotential, etc., and the first of the oxidation reaction carried out at the positive electrode is a reduced substance with a small precipitation potential (the actual precipitation electrode potential after considering the factors such as overpotential, etc.) algebraic value; the reduction reaction on the negative electrode is carried out by first precipitating an oxidation state substance with a large potential algebraic value.
Based on this principle, there are:
(1) at the cathode, metal ions such as Ca with very small electrode potential 2+ ，Na + And the like are not easily reduced at the cathode. Although it is used for
Are all greater than
But NO 3- Ion access to the cathode is difficult, NO near the cathode 3- At such a low concentration that NO is present 3- Is less than H + So on the cathode, H + The first electrons are obtained and reduced to active hydrogen. In order to react: 2H + +2e＝H 2 Mainly comprises the following steps.
(2) On the surface of the anode, a cathode is arranged,
regardless of the overpotential, there are:
Thus, the hydrogen generated at the cathode and the carbon dioxide generated at the anode provide necessary hydrogen source and carbon source for autotrophic denitrification of the autotrophic denitrifying bacteria.
(2) Biological principle: the electrode biomembrane method is mainly used for culturing autotrophic bacteria with denitrification capability to convert nitrate into nitrogen gas so as to achieve the aim of denitrification. Denitrifying bacteria are facultative anaerobes that use oxygen for aerobic respiration under aerobic conditions, but when the dissolved oxygen concentration is low, they draw oxygen from the nitrates, thereby converting the nitrates to nitrogen. The denitrifying bacteria are of various types, mainly including: achromobacter, aerobacter, alcaligenes, bacillus, flavobacterium, micrococcus, pseudomonas, proteus), thiobacillus, and the like. Denitrifying bacteria can be classified into heterotrophic denitrifying bacteria and autotrophic denitrifying bacteria according to the difference in carbon source used for the growth of the bacteria.
Heterotrophic denitrifying bacteria are denitrifying bacteria which utilize organic matters as nutrient sources, wherein the common organic matters comprise methanol, ethanol, acetic acid and the like, and the reaction formula is as follows:
NO 3- +1.08CH 3 OH+0.24H2CO 3 →0.06C 5 H 7 O 2 N+0.47N 2 +1.68H 2 O+HCO 3- ①
7.03CH 3 COOH+8.58NO 3- →0.58C 5 H 7 O 2 N+11.16CO 2 +8.58OH - +7.74H 2 O+4N 2 ②
autotrophic denitrifying bacteria are bacteria that use inorganic carbon such as bicarbonate ions and carbonic acid dissolved in water as a carbon source for bacterial synthesis. Active hydrogen, simple substance S and sulfide are used as inorganic electron donors, and the reaction formula is as follows:
55S+50NO 3- +38H 2 O+20CO 2 +4NH 4 →4C 5 H 7 O 2 N+55SO 4 2- +25N 2 +64H + ③
2.16NO 3- +7.24H 2 +0.8CO 2 →0.16C 5 H 7 O 2 N+N 2 +5.6H 2 O+2.16OH - ④
the reaction formula (4) is a reaction formula in which the hydrogen bacterium assimilates carbon dioxide by using active hydrogen as an energy source to convert nitrate into nitrogen. The hydrogen bacteria are various in types and are facultative autotrophic bacteria. They belong to the genera Pseudomonas, paracoccus, flavobacterium, alcaligenes, nocardia, etc., and most of the hydrogen bacteria are gram-negative bacteria, most of them are aerobic, and the other are anaerobic or facultative anaerobic. Such as Paracoccus denitrificans, for oxidizing H under anaerobic conditions 2 In the case of denitrification, nitric acid is used as the final electron acceptor. Most of the hydrogen bacteria are mesophilic bacteria, which are suitable for growth under neutral or slightly alkaline conditions, and among the chemoautotrophic bacteria, the hydrogen bacteria are the species with the fastest growth speed (the growth cycle is generally several hours), and the cell yield is also high. The cell yield per gram of energy is about 15 times of that of nitrosobacteria, 71 times of nitrifying bacteria and 24 times of sulfur bacteria respectively.
Based on the principle, the invention adopts the anaerobic electrobiological denitrification reactor 6 to form an anaerobic electrobiological denitrification system under the anaerobic working condition, a certain current is added in the flexible electrode assembly 1, the conductive fiber negative electrode 14 separates out hydrogen, the conductive fiber positive electrode 13 separates out carbon dioxide, bacteria utilize active hydrogen as energy and assimilate carbon dioxide, thus, the flexible electrode assembly 1 is applied to an anaerobic denitrification system, autotrophic denitrifying bacteria utilize active hydrogen and carbon dioxide generated by two poles, and denitrification action converts nitrate into nitrogen, thereby achieving the purpose of denitrification.
The anaerobic electro-biological denitrification reactor 6 forms an anaerobic electro-biological denitrification system under an anaerobic working condition, the system takes acetic acid or sodium acetate as a reaction substrate, as the number of sodium acetate hydrogen bond acceptors is 2, and the number of covalent bond units is 2, the oxidation reaction carried out at the positive electrode firstly precipitates a reduced substance with a small potential algebraic value; therefore, the hydrogen evolution reaction of the conductive fiber negative electrode 14 can be accelerated, the carbon dioxide can be quickly assimilated, and the removal of medium-concentration ammonia nitrogen and low-concentration nitrate nitrogen can be realized through denitrifying bacteria; the flexible electrode assembly 1 with stronger conductivity improves conductivity and stability, has low resistance and high structural strength, can be rolled and folded, is convenient to install, and the anaerobic electro-biological denitrification system composed of the flexible electrode assembly solves the problems that the traditional electrodes such as metal, graphite and the like have high manufacturing cost and are difficult to apply on a large scale.
The invention also provides the application of the flexible electrode assembly in the wastewater treatment process, the flexible electrode assembly 1 can be applied to the hydrolysis acidification process before aerobic or anaerobic treatment, the electrode biomembrane is utilized to carry out denitrification and denitrogenation, the metabolic pathway between microorganisms and pollutants is activated, and cyclic chain or long-chain organic matters which are not easy to biodegrade, in particular the non-degradable organic pollutants containing strong electronegative groups, such as nitroaromatics, halogenated compounds, azo compounds and the like, are hydrolyzed into short-chain low-molecular organic matters which are easy to degrade, the complexity or the oxidability of the non-degradable pollutants is reduced, the decoloration, the detoxication and the dehalogenation of the wastewater are enhanced, the COD removal efficiency of the whole process is improved, the biodegradability and the overall treatment efficiency of the wastewater are improved, and the overall operation cost is reduced.
The present invention will be described in more detail with reference to examples.
The first embodiment is as follows:
1. the main parameters are as follows:
(1) The size of the anaerobic electro-biological denitrification reactor 6 is as follows: the diameter is 500 mm and the height is 1500 mm;
(2) Effective volume of the anaerobic electro-biological denitrification reactor 6: 270L;
(3) Individual flexible electrode assemblies 1, size: the length is 4700 mm, the width is 1000 mm, and the thickness is 25 mm;
wherein: two pieces of cloth-like activated carbon fibers melt-blown with stainless steel 316S as a conductive fiber positive electrode 13 and a conductive fiber negative electrode 14, the size: the length is 4700 mm, the width is 1000 mm, and the thickness is 3 mm;
two metal flow guide nets 12 woven by stainless steel 316S wires, size: the length is 4700 mm, the width is 1000 mm, and the thickness is 0.8 mm;
two plastics compress tightly fixed network 15, size: the length is 4700 mm, the width is 1000 mm, and the thickness is 1.7 mm;
stainless steel fixing strips 16 and fixing pieces 17 are arranged.
The components are arranged according to a conductive fiber positive electrode 13, a metal flow guide net 12, a flexible insulating framework 11, a metal flow guide net 12 and a conductive fiber negative electrode 14, the outer sides of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 are respectively pressed by plastic pressing fixing nets 15, and then stainless steel fixing strips 16 are pressed at intervals and fixed into a whole by fixing pieces 17 to form the flexible electrode assembly 1.
(4) Insulating isolation net 2: size: the length is 4700 mm, the width is 1000 mm, and the thickness is 20 mm;
(5) The submersible mixer: one QJB 0.37/6; 220V power supply, rotating speed 100-900r/min (with frequency converter)
(6) A direct-current power supply: the output voltage is 0-12V, the actual use voltage is 0.8V, and the maximum output current is 5A.
The flexible electrode assembly 1 and the insulating isolation net 2 are stacked and rolled into a cylinder together to obtain a cylindrical insulating and separating electric biological assembly with the interval of 2cm, and the cylindrical electric biological assembly electrode is provided with a conductive fiber negative electrode 14, a conductive fiber positive electrode 13, a conductive fiber negative electrode 14 and a conductive fiber positive electrode 13 from inside to outside in sequence, and the interval is 2cm. The positive electrode lead-out wire 4 is connected with the positive electrode of the direct current power supply 7, the positive electrode lead-out wire 4 is connected with the negative electrode of the direct current power supply 7, and the flexible electrode assembly of the whole reactor is connected with the direct current stabilized power supply in series through a flow guide net lead woven by stainless steel 316S wires to form an anaerobic electrobiological denitrification system (EAMS). The reactor is a sequencing batch anaerobic biological denitrification system.
Selecting target pollutant ammonia nitrogen as a treatment object, and testing the degradation performance of the target pollutant ammonia nitrogen on the ammonia nitrogen.
2. The start-up conditions were as follows:
(1) EAMS System operation
Anaerobic start is carried out under the condition of room temperature, the voltage of a direct current stabilized power supply is changed with different tests in the test, the stirring speed of the plug flow type stirrer 62 is controlled at 500r/min, anaerobic ammonia oxidizing bacteria to be cultured are generated under the anoxic condition when the anaerobic ammonia oxidation reaction test is started, and therefore the experimental device is not sealed, but is selectively cultured in an open way without aeration so as to keep the anoxic condition.
(2) Acclimatizing and culturing the biological membrane on the surface of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14
The sludge used in the process is obtained from anaerobic sludge domestication of a transverse sentry sewage treatment plant (second stage) in Shenzhen city, the ratio of VSS (volatile solid) to TSS (suspended matter concentration) is 0.67, the sludge water content is about 97%, the sludge sedimentation ratio is 35%, and the suspended solid concentration of the mixed liquid is about 2100mg/L. Placing the activated sludge and the prepared wastewater in a device for anaerobic stirring, and connecting a direct current power supply 7 for culturing and domesticating the sludge. Only basic nutrient substances and sodium acetate are added when the culture period begins to be two weeks, and ammonia nitrogen and nitrite ions are added for acclimatization after the sludge is adapted. The concentration of the ammonia nitrogen wastewater added for the first time is 10mg/L, and the sludge is changed every other day (namely the hydraulic retention time is 48 h). When water is changed, the supernatant is poured out from the water outlet 67 of the anaerobic biological denitrification reactor 6, the water changing proportion is 2/3, namely 1/3 of the activated sludge at the bottom is reserved, then the reconfigured wastewater is added, the changed sludge supernatant is precipitated again, then the supernatant is discharged, and a small amount of activated sludge at the bottom is poured back into the reactor, so that the sludge backflow is ensured and the sludge loss is avoided. And (4) adding 10mg/L ammonia nitrogen when water is distributed in the new domestication period after each domestication period is finished, and repeating the steps until the ammonia nitrogen concentration is increased to the standard ammonia nitrogen concentration (75 mg/L) required by the experiment. In addition, when the water distribution concentration of ammonia nitrogen is increased by 10mg/L, the domestication period is increased by one week so as to facilitate the adaptation of strains, and the strains cannot die too fast. After more than 60 days of acclimation, a layer of microorganisms is attached to the surfaces of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14) in the anaerobic electro-biological denitrification reactor 6, and the phenomenon shows that a biomembrane electrode is formed around the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 in the anaerobic electro-biological denitrification reactor 6, which is beneficial to the degradation of ammonia nitrogen by microorganisms.
(3) Designing EAMS system operating parameters
In an ammonia nitrogen degradation effect test in an EAMS system, when the initial ammonia nitrogen concentration is 75mg/L, the voltage is adjusted to be 0.8V, the current density of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 is 0.05mA/cm, the temperature T =25 +/-2 ℃, the pH =7.2, and other conditions are unchanged.
The instrument adopted in the embodiment is a TU-1810ASPC ultraviolet-visible spectrophotometer, and the maximum absorption wavelength of ammonia nitrogen in the wastewater measured by the Nashin reagent is 420nm through spectral scanning measurement, so that the absorption wavelength of the instrument is controlled to be 420run, water is used as a blank control, and ammonia nitrogen in the wastewater is measured by a Nashin reagent spectrophotometry (HJ 535-2009) for measuring ammonia nitrogen in water quality.
The degradation effect of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the EAMS system in 12 hours is shown in FIG. 7:
(1) In an EAMS system, the degradation rate of nitrite nitrogen is very high, the nitrite nitrogen with the concentration of 56mg/L is completely degraded after 5 hours, and the degradation rate reaches 100 percent.
(2) The EAMS system has the effect of degrading ammonia nitrogen, and finds that the ammonia nitrogen content is gradually degraded along with the increase of the treatment time, and the degradation rate of 75mg/L ammonia nitrogen reaches 86.66% after 12 hours.
(3) The EAMS system degrades nitrate nitrogen slowly and hardly continues to degrade after 5 hours.
Example two:
the present embodiment uses an anaerobic electro-biological denitrification reactor 6 (EAMS) similar to the embodiment, except that the present embodiment does not have the metal current-guiding net 12, and the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 are replaced by the conventional activated carbon fiber as the electrode, and the starting conditions are as follows:
(1) EAMS System operation
The same as in the first embodiment.
(2) Acclimatization and culture of traditional biological membrane on the surface of activated carbon fiber
The procedure is the same as in the first embodiment.
(3) Designing EAMS system operating parameters
The operation parameters in the ammonia nitrogen degradation effect test in the EAMS system are the same as those in the first embodiment, the voltage is adjusted to be 0.8V when the initial ammonia nitrogen concentration is 75mg/L, the activated carbon fiber electrode passes through the current density of 0.05mA/cm, the temperature T =25 +/-2 ℃, the pH =7.2, and other conditions are unchanged.
The instrument that this embodiment adopted is TU-1810ASPC ultraviolet-visible spectrophotometer, and the biggest absorption wavelength that can know ammonia nitrogen in the nah reagent survey waste water by spectral scan survey is 420nm, so with the absorption wavelength control of instrument at 420run, use water as blank control, adopt "determination of quality of water ammonia nitrogen nah reagent spectrophotometry (HJ 535-2009)" to survey the ammonia nitrogen in the waste water.
The present example examines the degradation effect of the system on ammonia nitrogen, nitrite nitrogen and nitrate nitrogen within 12h, and the results are shown in fig. 8:
(1) According to an EAMS system, the degradation rate of nitrite nitrogen with the concentration of 56mg/L reaches 44.66% after 12 hours.
(2) According to the EAMS system, the ammonia nitrogen content is increased along with the treatment time, the ammonia nitrogen is gradually degraded, and the degradation rate of the ammonia nitrogen with the concentration of 75mg/L reaches 52% after 12 hours.
(3) In an EAMS system, the degradation rate of nitrate nitrogen with the concentration of 10mg/L reaches 55.35 percent after 12 hours.
As can be seen from the comparison of the first embodiment, the metal current conducting mesh 2 in the flexible electrode assembly 1 of the present invention, the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14, are combined to be far higher than the traditional activated carbon fiber electrode, and have degradation effects on ammonia nitrogen, nitrite nitrogen and nitrate nitrogen.
Example three:
using an anaerobic electro-biological denitrification system (EAMS) similar to that of the example, acetic acid was applied to a chemical feed port 65 provided in a water inlet 64 at the bottom of the anaerobic electro-biological denitrification reactor 6 as a reaction substrate to examine the denitrification effect. The start-up conditions were as follows:
(1) EAMS System operation
Anaerobic start is carried out under the condition of room temperature, the voltage of the direct current power supply 7 is changed with different tests in the test, the rotating speed of the plug flow type stirrer 62 is also controlled at 500r/min, and because the anaerobic ammonia oxidation bacteria to be cultured occur under the anoxic condition when the anaerobic ammonia oxidation reaction test is started, the experimental device is not sealed, but is selectively cultured in an open way without aeration so as to keep the anoxic condition.
(2) Domesticating and culturing the biological membranes on the surfaces of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 is the same as the first embodiment;
(3) Designing EAMS system operating parameters
The operation parameters in the ammonia nitrogen degradation effect test in the EAMS system are the same as those in the first embodiment, when the initial ammonia nitrogen concentration is 75mg/L, the voltage is adjusted to be 0.8V, the current density of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 is 0.05mA/cm, acetic acid is applied to a dosing port 65 on a water inlet 64 at the bottom of the anaerobic electro-biological denitrification reactor 6 to serve as a reaction substrate, the dosing amount is calculated by taking the carbon-nitrogen ratio as 2, the T =25 +/-2 ℃, the pH =7.2, and other conditions are unchanged.
The instrument adopted in the embodiment is a TU-1810ASPC ultraviolet-visible spectrophotometer, and the maximum absorption wavelength of ammonia nitrogen in the wastewater measured by the Nashin reagent is 420nm through spectral scanning measurement, so that the absorption wavelength of the instrument is controlled to be 420run, water is used as a blank control, and ammonia nitrogen in the wastewater is measured by a Nashin reagent spectrophotometry (HJ 535-2009) for measuring ammonia nitrogen in water quality.
In this example, the degradation effect of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the EAMS system is within 12h, and the result is shown in fig. 9:
(1) In the EAMS system, the degradation rate of the nitrite nitrogen is very fast, the nitrite nitrogen with the concentration of 56mg/L is almost completely degraded within 4 hours, and the degradation rate reaches 100 percent, which is not much different from the first embodiment.
(2) The EAMS system has the degradation effect on ammonia nitrogen, and the ammonia nitrogen content is found to increase along with the treatment time, the ammonia nitrogen content continues to degrade, and the degradation rate of the ammonia nitrogen with the concentration of 75mg/L reaches 94.66% in 12 hours.
(3) The EAMS system has a degradation rate of 96% after 12 hours for nitrate nitrogen with the concentration of 10 mg/L.
The result shows that acetic acid is applied to a dosing port 65 on a water inlet 64 at the bottom of the anaerobic electrical biological denitrification reactor 6 to serve as a reaction substrate, the dosing amount is calculated by taking the carbon-nitrogen ratio as 2, the precipitation of hydrogen in a negative electrode is facilitated, hydrogen bacteria use hydrogen as energy and assimilate carbon dioxide, therefore, by adopting the anaerobic electrical biological denitrification system (EAMS), two forms of hydrogen products are reacted and are respectively active hydrogen and hydrogen molecules, autotrophic denitrifying bacteria use the active hydrogen and the carbon dioxide generated by the two poles, and the denitrification effect converts nitrate into nitrogen, thereby achieving the aim of denitrification.
Example four:
with the anaerobic electro-biological denitrification system (EAMS) as in the example, the flexible electrode assembly 1 is provided with the metal flow guiding net 12, the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 are woven by high-conductivity carbon fiber yarns, and acetic acid is applied to the chemical adding port 65 on the water inlet 64 at the bottom of the anaerobic electro-biological denitrification reactor 6 as a reaction substrate to examine the denitrification effect. The start-up conditions were as follows:
(1) The running conditions of the EAMS system are the same as those of the embodiment;
(2) The acclimatization culture of the biological membranes on the surfaces of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 is the same as that of the embodiment;
(3) The operation parameters of the EAMS system are designed to be the same as those of the embodiment;
the instrument adopted in the embodiment is a TU-1810ASPC ultraviolet-visible spectrophotometer, and the maximum absorption wavelength of ammonia nitrogen in the wastewater measured by the Nashin reagent is 420nm through spectral scanning measurement, so that the absorption wavelength of the instrument is controlled to be 420run, water is used as a blank control, and ammonia nitrogen in the wastewater is measured by a Nashin reagent spectrophotometry (HJ 535-2009) for measuring ammonia nitrogen in water quality.
The results of the degradation effect of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the EAMS system within 12h are shown in FIG. 10:
(1) The EAMS system, the degradation rate of 56mg/L nitrite nitrogen is not different from the third embodiment.
(2) The degradation effect of the EAMS system on ammonia nitrogen is found, the ammonia nitrogen content is increased along with the treatment time, the ammonia nitrogen content is continuously degraded, and the 12-hour degradation rate of the ammonia nitrogen with the concentration of 75mg/L reaches 94.00 percent, which is not much different from that of the third embodiment.
(3) In the EAMS system, the degradation rate of nitrate nitrogen of 10mg/L reaches 95.60 percent after 12 hours, and the difference with the third embodiment is not great.
As a result, the denitrification effect of the conductive fiber positive electrode 13 and the conductive fiber negative electrode 14 which are made of the activated carbon fiber sprayed with the conductive metal layer is basically the same.
The above-described embodiments of the present invention are merely exemplary and not intended to limit the present invention, and those skilled in the art may make various modifications, substitutions and improvements without departing from the spirit of the present invention.
Claims (11)
1. The flexible electrode assembly is characterized by comprising a flexible insulating framework, and a conductive fiber positive electrode and a conductive fiber negative electrode which are respectively attached to two sides of the flexible insulating framework and are not conducted, wherein the conductive fiber positive electrode and the conductive fiber negative electrode are formed by flexible high-conductivity carbon fibers or activated carbon fibers coated with conductive metal layers, metal current-conducting nets are respectively clamped between the conductive fiber positive electrode and the conductive fiber negative electrode and between the flexible insulating framework, and the outer sides of the conductive fiber positive electrode and the conductive fiber negative electrode are respectively provided with a pressing fixing net for connecting the flexible insulating framework, the conductive fiber positive electrode, the conductive fiber negative electrode and the metal current-conducting nets into a whole.
2. The flexible electrode assembly of claim 1, wherein the flexible insulating scaffolding is a geomembrane of meltblown PP material.
3. The flexible electrode assembly of claim 1, wherein the metal flow directing mesh is woven from stainless steel 316S filaments having a monofilament diameter of 0.1-2 mm.
4. The flexible electrode assembly of claim 1, wherein the flexible highly conductive carbon fibers are woven from a blend of polypropylene fibers and conductive carbon fibers.
5. The flexible electrode assembly of claim 4, wherein the flexible highly conductive carbon fibers are formed by weaving 1K-12K conductive carbon fibers and 100-300D polypropylene fibers into a plurality of large and horizontal grid-shaped units, each of the large grid-shaped units comprises four small grid-shaped units, each of the large grid-shaped units is framed by thick warp and thick weft of the mixed twisted yarn of the conductive carbon fibers and the polypropylene fibers, the middle large cross-shaped rib is formed by thick warp and thick weft of the conductive carbon fibers, the middle small cross-shaped rib is formed by warp and weft of the conductive carbon fibers, and a plurality of monofilament and weft of the polypropylene fibers are arranged on both sides of each of the small cross-shaped ribs to form a curtain-type warp grid cloth.
6. The flexible electrode assembly of claim 5, wherein a cross-shaped cut is made at the position of the small cross-shaped rib in the middle of each small rectangular unit by using a cutter, so that the thread end of the conductive carbon fiber after each cross-shaped rib is cut off floats out from the cut and freely stretches outwards; or the polypropylene fiber monofilament warp threads and the fine weft threads are cut at the edge of the small cross-shaped rib in the middle of each small Chinese character tian-shaped unit, so that four L-shaped cuts are formed in each small Chinese character tian-shaped unit, and the cut polypropylene fiber thread ends float out from the cuts and freely stretch outwards.
7. The flexible electrode assembly according to claim 1, wherein the conductive metal layer of the activated carbon fiber is formed by dipping the activated carbon fiber cloth in melamine polyphosphate with a concentration of 10-15% for 2 hours, and then spraying a stainless steel 316S wire on one surface of the activated carbon fiber cloth by melting in a plasma spraying manner under compressed air, the conductive metal layer is located on the surface opposite to the metal current-guiding net, and the mass of the stainless steel 316S wire sprayed on the surface of the activated carbon fiber cloth is 10-15% of the mass of the activated carbon fiber cloth.
8. The flexible electrode assembly of claim 7, wherein the activated carbon fiber cloth is made by the steps of:
s1, dipping the viscose-based non-woven fabric for 2 hours by using melamine polyphosphate with the concentration of 10-15%;
s2, pre-oxidizing for 30-60 min at the temperature of 200-250 ℃;
s3, carbonizing at 250-350 ℃ for 30-60 min under a protective atmosphere;
s4, performing pore-forming treatment on the carbonized viscose-based non-woven fabric by using water vapor, and then performing activation treatment at the temperature of 900-1000 ℃ for 6-8 h;
and S5, washing with 20% sulfuric acid, washing with boiling deionized water to be neutral, and drying to obtain the activated carbon fiber cloth.
9. An anaerobic electro-biological denitrification system, characterized in that, the anaerobic electro-biological denitrification reactor is provided with one or more flexible electrode assemblies as described in any one of claims 1-8 arranged in a container or a water tank, a stirrer is arranged at the bottom of the container or the water tank, the conductive fiber positive electrode and the conductive fiber negative electrode in the flexible electrode assemblies are respectively connected with a power supply through a metal diversion net communicated with the conductive fiber positive electrode and the conductive fiber negative electrode, denitrifying bacteria are acclimated by an external electric field to form a biomembrane electrode, the conductive fiber negative electrode is made to precipitate hydrogen, the conductive fiber positive electrode precipitates carbon dioxide, and active hydrogen and carbon dioxide are used as denitrification energy sources to be applied to denitrification of an anaerobic denitrification system.
10. The anaerobic electro-biological denitrification system of claim 9 wherein a dosing port for acetic acid or sodium acetate is provided in the water inlet line of the vessel or the tank.
11. The application of the flexible electrode assembly in the wastewater treatment process is characterized in that the flexible electrode assembly is applied to a hydrolysis acidification process before anaerobic or aerobic treatment, so that organic matters which are not easy to biodegrade and are in a ring chain or a long chain are hydrolyzed into organic matters which are easy to degrade and are in a short chain and low molecules.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210731562 | 2022-06-25 | ||
| CN2022107315628 | 2022-06-25 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115403135A true CN115403135A (en) | 2022-11-29 |
| CN115403135B CN115403135B (en) | 2024-01-09 |
Family
ID=84163282
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211075369.XA Active CN115403135B (en) | 2022-06-25 | 2022-09-05 | Flexible electrode assembly, anaerobic electrobiological denitrification system and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115403135B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118684331A (en) * | 2024-08-22 | 2024-09-24 | 深圳市臻鼎环保科技有限公司 | Pyrite electrode and preparation method thereof |
| CN118684331B (en) * | 2024-08-22 | 2024-11-19 | 深圳市臻鼎环保科技有限公司 | Pyrite electrode and preparation method thereof |
Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH103947A (en) * | 1996-06-14 | 1998-01-06 | Toray Ind Inc | Battery |
| JP2004074004A (en) * | 2002-08-16 | 2004-03-11 | Hiroyasu Ogawa | Method of cleaning water in closed water area by using fibrous material |
| CN2616529Y (en) * | 2003-04-24 | 2004-05-19 | 周增炎 | Suspension biological vector |
| CN101014218A (en) * | 2007-01-30 | 2007-08-08 | 东华大学 | Far infrared flexible surface heating element with high emissivity |
| JP2010099614A (en) * | 2008-10-24 | 2010-05-06 | Seiren Co Ltd | Contact material for water treatment |
| CN102659221A (en) * | 2012-05-10 | 2012-09-12 | 刘娟 | Electro-catalytic oxidation material for wastewater treatment, preparation method and application |
| CN102864463A (en) * | 2012-08-29 | 2013-01-09 | 杭州净洋环保科技有限公司 | H2 collection system for kitchen wastes |
| CN106277694A (en) * | 2016-02-25 | 2017-01-04 | 上海同臣环保有限公司 | The anode material of electronic/elastic squeezer of high pressure coupling and installation and application thereof |
| CN106957102A (en) * | 2017-04-19 | 2017-07-18 | 广东工业大学 | A kind of girdle type biological membrane electrode electrochemical appliance and its application |
| CN108091497A (en) * | 2017-12-06 | 2018-05-29 | 中国科学院上海技术物理研究所 | A kind of preparation method of multidimensional structure carbon fiber flexible electrode |
| CN207713468U (en) * | 2017-11-27 | 2018-08-10 | 上海辨洁环保科技有限公司 | A kind of adsorption module |
| CN110253983A (en) * | 2019-06-19 | 2019-09-20 | 安徽天富环保科技材料有限公司 | A kind of activated carbon fiber cloth and preparation method thereof |
| US20200227803A1 (en) * | 2013-07-01 | 2020-07-16 | Pei Zhang | Biological battery and biological cathode electrode |
| CN114195339A (en) * | 2021-11-22 | 2022-03-18 | 深圳市政水环境技术有限公司 | Synchronous sludge reduction method, device and system for recycling sludge carbon source |
| CN216639036U (en) * | 2022-01-24 | 2022-05-31 | 上海浩为环境工程有限公司 | Biofilm filter screen carrier filler monomer and biofilm filter screen carrier filler |
-
2022
- 2022-09-05 CN CN202211075369.XA patent/CN115403135B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH103947A (en) * | 1996-06-14 | 1998-01-06 | Toray Ind Inc | Battery |
| JP2004074004A (en) * | 2002-08-16 | 2004-03-11 | Hiroyasu Ogawa | Method of cleaning water in closed water area by using fibrous material |
| CN2616529Y (en) * | 2003-04-24 | 2004-05-19 | 周增炎 | Suspension biological vector |
| CN101014218A (en) * | 2007-01-30 | 2007-08-08 | 东华大学 | Far infrared flexible surface heating element with high emissivity |
| JP2010099614A (en) * | 2008-10-24 | 2010-05-06 | Seiren Co Ltd | Contact material for water treatment |
| CN102659221A (en) * | 2012-05-10 | 2012-09-12 | 刘娟 | Electro-catalytic oxidation material for wastewater treatment, preparation method and application |
| CN102864463A (en) * | 2012-08-29 | 2013-01-09 | 杭州净洋环保科技有限公司 | H2 collection system for kitchen wastes |
| US20200227803A1 (en) * | 2013-07-01 | 2020-07-16 | Pei Zhang | Biological battery and biological cathode electrode |
| CN106277694A (en) * | 2016-02-25 | 2017-01-04 | 上海同臣环保有限公司 | The anode material of electronic/elastic squeezer of high pressure coupling and installation and application thereof |
| CN106957102A (en) * | 2017-04-19 | 2017-07-18 | 广东工业大学 | A kind of girdle type biological membrane electrode electrochemical appliance and its application |
| CN207713468U (en) * | 2017-11-27 | 2018-08-10 | 上海辨洁环保科技有限公司 | A kind of adsorption module |
| CN108091497A (en) * | 2017-12-06 | 2018-05-29 | 中国科学院上海技术物理研究所 | A kind of preparation method of multidimensional structure carbon fiber flexible electrode |
| CN110253983A (en) * | 2019-06-19 | 2019-09-20 | 安徽天富环保科技材料有限公司 | A kind of activated carbon fiber cloth and preparation method thereof |
| CN114195339A (en) * | 2021-11-22 | 2022-03-18 | 深圳市政水环境技术有限公司 | Synchronous sludge reduction method, device and system for recycling sludge carbon source |
| CN216639036U (en) * | 2022-01-24 | 2022-05-31 | 上海浩为环境工程有限公司 | Biofilm filter screen carrier filler monomer and biofilm filter screen carrier filler |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118684331A (en) * | 2024-08-22 | 2024-09-24 | 深圳市臻鼎环保科技有限公司 | Pyrite electrode and preparation method thereof |
| CN118684331B (en) * | 2024-08-22 | 2024-11-19 | 深圳市臻鼎环保科技有限公司 | Pyrite electrode and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115403135B (en) | 2024-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107098459B (en) | Electrochemical device and method for treating high-concentration ammonia nitrogen organic wastewater | |
| CN108183251B (en) | Microbial fuel cell BCS1-MFC system for treating low C/N wastewater and wastewater treatment method thereof | |
| CN102276064B (en) | Anaerobic-aerobic integrated microbial fuel cell wastewater treatment system | |
| CN112573667B (en) | Sewage treatment device and method based on algae-bacteria symbiotic electrochemical system | |
| CN109179860A (en) | A kind of method of Recalcitrant chemicals and degradation excess sludge in synchronous catalysis oxidation secondary effluent | |
| CN105152351A (en) | Photoelectric artificial wetland and application thereof | |
| CN102110835A (en) | Microbe fuel cell device for enhanced nitrogen removal in AAO sewage treatment technology | |
| CN111530267B (en) | Device and method for denitration of flue gas by combining microbial fuel cell with microbial electrolytic cell | |
| CN112607864A (en) | Electrochemical performance-enhanced bacteria-algae membrane aeration biomembrane reactor system and application thereof | |
| CN106630177A (en) | Method and device for treating coking wastewater and producing hydrogen gas by microbial electrolysis cell | |
| CN109912145B (en) | Aerobic granular sludge power generation device | |
| CN109052668A (en) | A kind of the cultivation biogas slurry treatment device and biogas slurry treatment method of solar energy electric field collaboration phycomycete metabolism | |
| CN112174293A (en) | Electric-enhanced bioretention system for removing low-concentration antibiotics | |
| CN111646635A (en) | Method for strengthening performance of constructed wetland-microbial fuel cell coupling system | |
| CN115403135B (en) | Flexible electrode assembly, anaerobic electrobiological denitrification system and application | |
| CN103739161A (en) | Low-energy-consumption degradation-resistant organic wastewater recycling method | |
| CN107673566B (en) | Device and method for treating black and odorous water body | |
| CN214400167U (en) | Sewage treatment device based on algae bacterium symbiosis electrochemical system | |
| CN114275879B (en) | Device and method for treating sewage by adopting light-transmitting conductive biocathode bacteria-algae bioelectrochemical system | |
| CN215924693U (en) | CW-MFC device for treating wastewater containing Pb (II) | |
| CN218146022U (en) | Flexible electrode assembly and anaerobic biological denitrification device | |
| CN213388232U (en) | Electric-enhanced bioretention system for removing low-concentration antibiotics | |
| CN112939196A (en) | Coke electrode microbial fuel cell constructed wetland system, operation method and application | |
| CN209872695U (en) | Integrated microbial desalination cell-artificial wetland device | |
| CN105948223B (en) | A kind of microbial fuel cell unit of three battery system and its application |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |