CN114988547A - Fluorine removal agent, preparation method thereof and method for deep fluorine removal by adopting fluorine removal agent - Google Patents
Fluorine removal agent, preparation method thereof and method for deep fluorine removal by adopting fluorine removal agent Download PDFInfo
- Publication number
- CN114988547A CN114988547A CN202210673977.4A CN202210673977A CN114988547A CN 114988547 A CN114988547 A CN 114988547A CN 202210673977 A CN202210673977 A CN 202210673977A CN 114988547 A CN114988547 A CN 114988547A
- Authority
- CN
- China
- Prior art keywords
- fluorine
- chitosan
- sludge
- tank
- agent
- 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
- 239000011737 fluorine Substances 0.000 title claims abstract description 77
- 229910052731 fluorine Inorganic materials 0.000 title claims abstract description 77
- 239000003795 chemical substances by application Substances 0.000 title claims abstract description 74
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 title claims abstract description 69
- 238000000034 method Methods 0.000 title claims abstract description 44
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims abstract description 62
- 239000010802 sludge Substances 0.000 claims abstract description 62
- 229920001661 Chitosan Polymers 0.000 claims abstract description 54
- 238000004062 sedimentation Methods 0.000 claims abstract description 44
- 239000002244 precipitate Substances 0.000 claims abstract description 24
- 229910021645 metal ion Inorganic materials 0.000 claims abstract description 21
- 238000006115 defluorination reaction Methods 0.000 claims abstract description 19
- -1 fluorine ions Chemical class 0.000 claims abstract description 10
- 238000001179 sorption measurement Methods 0.000 claims abstract description 8
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 60
- 238000002156 mixing Methods 0.000 claims description 51
- 239000000126 substance Substances 0.000 claims description 47
- 239000011259 mixed solution Substances 0.000 claims description 39
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 38
- 239000002351 wastewater Substances 0.000 claims description 30
- 238000005189 flocculation Methods 0.000 claims description 28
- 230000016615 flocculation Effects 0.000 claims description 28
- 238000003756 stirring Methods 0.000 claims description 25
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical group Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 claims description 24
- 239000000203 mixture Substances 0.000 claims description 24
- 239000000243 solution Substances 0.000 claims description 21
- 239000000843 powder Substances 0.000 claims description 19
- 238000001035 drying Methods 0.000 claims description 17
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 17
- 229920002401 polyacrylamide Polymers 0.000 claims description 15
- 239000011575 calcium Substances 0.000 claims description 14
- 239000013522 chelant Substances 0.000 claims description 14
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 claims description 10
- 238000007599 discharging Methods 0.000 claims description 9
- 239000013078 crystal Substances 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 8
- 150000002910 rare earth metals Chemical class 0.000 claims description 8
- 229910016569 AlF 3 Inorganic materials 0.000 claims description 7
- 238000004140 cleaning Methods 0.000 claims description 7
- 230000006196 deacetylation Effects 0.000 claims description 7
- 238000003381 deacetylation reaction Methods 0.000 claims description 7
- 238000000227 grinding Methods 0.000 claims description 7
- 238000010992 reflux Methods 0.000 claims description 7
- 150000003839 salts Chemical class 0.000 claims description 7
- 229910017768 LaF 3 Inorganic materials 0.000 claims description 6
- VYLVYHXQOHJDJL-UHFFFAOYSA-K cerium trichloride Chemical compound Cl[Ce](Cl)Cl VYLVYHXQOHJDJL-UHFFFAOYSA-K 0.000 claims description 6
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 5
- HSJPMRKMPBAUAU-UHFFFAOYSA-N cerium(3+);trinitrate Chemical compound [Ce+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O HSJPMRKMPBAUAU-UHFFFAOYSA-N 0.000 claims description 4
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 claims description 4
- ICAKDTKJOYSXGC-UHFFFAOYSA-K lanthanum(iii) chloride Chemical compound Cl[La](Cl)Cl ICAKDTKJOYSXGC-UHFFFAOYSA-K 0.000 claims description 4
- 238000009777 vacuum freeze-drying Methods 0.000 claims description 4
- 150000002505 iron Chemical class 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 2
- 229910052791 calcium Inorganic materials 0.000 claims description 2
- 229910000420 cerium oxide Inorganic materials 0.000 claims description 2
- UNJPQTDTZAKTFK-UHFFFAOYSA-K cerium(iii) hydroxide Chemical compound [OH-].[OH-].[OH-].[Ce+3] UNJPQTDTZAKTFK-UHFFFAOYSA-K 0.000 claims description 2
- 230000000694 effects Effects 0.000 claims description 2
- YXEUGTSPQFTXTR-UHFFFAOYSA-K lanthanum(3+);trihydroxide Chemical compound [OH-].[OH-].[OH-].[La+3] YXEUGTSPQFTXTR-UHFFFAOYSA-K 0.000 claims description 2
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims description 2
- 238000000926 separation method Methods 0.000 claims 2
- 150000001875 compounds Chemical class 0.000 claims 1
- 238000000975 co-precipitation Methods 0.000 abstract description 14
- 238000005054 agglomeration Methods 0.000 abstract description 6
- 230000002776 aggregation Effects 0.000 abstract description 6
- 238000004090 dissolution Methods 0.000 abstract description 4
- 229910052751 metal Inorganic materials 0.000 abstract description 4
- 239000002184 metal Substances 0.000 abstract description 4
- 239000002245 particle Substances 0.000 abstract description 3
- 230000002378 acidificating effect Effects 0.000 abstract description 2
- 239000008367 deionised water Substances 0.000 description 15
- 229910021641 deionized water Inorganic materials 0.000 description 15
- 229910018084 Al-Fe Inorganic materials 0.000 description 11
- 229910018192 Al—Fe Inorganic materials 0.000 description 11
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 description 10
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 6
- 238000005119 centrifugation Methods 0.000 description 5
- 238000004108 freeze drying Methods 0.000 description 5
- 238000007710 freezing Methods 0.000 description 5
- 230000008014 freezing Effects 0.000 description 5
- 238000005057 refrigeration Methods 0.000 description 5
- 238000009388 chemical precipitation Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- 239000000701 coagulant Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 229910052746 lanthanum Inorganic materials 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- 229910004261 CaF 2 Inorganic materials 0.000 description 2
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 230000001112 coagulating effect Effects 0.000 description 2
- 239000000084 colloidal system Substances 0.000 description 2
- 239000003814 drug Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 2
- 230000001376 precipitating effect Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 229940037003 alum Drugs 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004925 denaturation Methods 0.000 description 1
- 230000036425 denaturation Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000003837 high-temperature calcination Methods 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000011221 initial treatment Methods 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000012716 precipitator Substances 0.000 description 1
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000013049 sediment Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 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
- C02F9/00—Multistage treatment of water, waste water or sewage
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/28—Treatment of water, waste water, or sewage by sorption
- C02F1/286—Treatment of water, waste water, or sewage by sorption using natural organic sorbents or derivatives thereof
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
- C02F1/56—Macromolecular compounds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/58—Treatment of water, waste water, or sewage by removing specified dissolved compounds
- C02F1/583—Treatment of water, waste water, or sewage by removing specified dissolved compounds by removing fluoride or fluorine compounds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F2001/007—Processes including a sedimentation step
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/12—Halogens or halogen-containing compounds
- C02F2101/14—Fluorine or fluorine-containing compounds
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/30—Wastewater or sewage treatment systems using renewable energies
- Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Separation Of Suspended Particles By Flocculating Agents (AREA)
- Removal Of Specific Substances (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
The invention discloses a defluorinating agent and a preparation method thereof and a method for deeply defluorinating by adopting the defluorinating agent, wherein chitosan is used as a framework of the defluorinating agent, and is fully chelated in acetic acid through a co-precipitate of the chitosan and metal ions, so that the mechanical strength of the chitosan under an acidic condition is effectively improved, and meanwhile, secondary pollution caused by metal ion reverse dissolution can be effectively avoided; in addition, the coprecipitation formed by a plurality of metal ions can not only enlarge the applicable pH range of the fluorine removal agent, but also greatly improve the adsorption removal performance of fluorine ions and the settling speed of sludge flocs; the preparation method of the invention obtains various metal ion coprecipitations by a reverse coprecipitation method, the particle size of the coprecipitations is uniform, and no agglomeration or agglomeration phenomenon exists, so that the metal active sites on the chitosan are uniformly dispersed, and the adsorption performance of the defluorinating agent is improved; finally, make the best ofWhen the defluorinating agent is used for deep defluorination, the sludge in a certain proportion in the sedimentation tank is refluxed, so that the density of flocs can be effectively increased, the sedimentation speed of the sludge flocs is increased, the removal rate of fluorine ions reaches over 95 percent, and F is ‑ The concentration is reduced to below 1.0 mg/L.
Description
Technical Field
The invention relates to a fluorine removing agent, a preparation method of the fluorine removing agent, and finally a method for deep fluorine removal by adopting the fluorine removing agent.
Background
The fluorine-containing wastewater is common wastewater in the electronic industry and has the characteristics of large water quantity and strong biological toxicity. The commonly used defluorination methods at present include chemical precipitation and coagulation precipitation. The chemical precipitation method generally uses lime water as a precipitator and Ca 2+ And F - Production of CaF 2 Precipitating to separate the fluoride ions from the wastewater. The chemical precipitation method has the advantages of large water treatment amount and low cost, but the fluorine concentration is reduced to 10-20 mg/L after the treatment by the method, and the fluorine concentration still exceeds the effluent F specified by the national environmental protection standard - Is less than 1mg/L, so the chemical precipitation method is only suitable for the primary treatment of the fluorine-containing wastewater. In addition, the dosage of the medicament used in the process is large, the water content of the sludge is high, and the recycling is difficult. The coagulating sedimentation method is that coagulant is added into the fluorine-containing waste water, after the pH value is properly regulated, flocculent colloid is formed, the colloid is combined with fluorine ions in the water through chemical or physical action, and finally, precipitate is formed and discharged. The common coagulant mainly takes aluminum salt and iron salt as main components, and specifically comprises alumina, polyaluminium chloride, polyferric sulfate, ferric chloride and the like. By coagulating sedimentation asThe fluorine wastewater advanced treatment method can be used for treating effluent F - The concentration is reduced to below 1.0mg/L, but the requirements of the coagulant on the reaction pH are strict, the generated floc is loose, the settling property is poor, and Al 3+ The reverse dissolution of the sodium hydroxide can cause secondary pollution and harm human health.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a defluorinating agent which has wide pH application range and high density of formed flocs in the defluorination application process, thereby improving the sludge settling property; the invention also aims to provide a preparation method of the fluorine removal agent and a method for deeply removing fluorine by using the fluorine removal agent.
The technical scheme is as follows: the defluorinating agent is prepared by the following components in percentage by mass, chitosan is used as a biomolecule framework, and an aluminum-iron-rare earth metal blend is loaded on the framework to form a chelate with a plurality of active sites; wherein, the aluminum salt: iron salt: rare earth materials: and (3) chitosan: the mass ratio of acetic acid is 5-10: 5-10: 15-20: 5-10: 3 to 5.
Wherein the deacetylation degree of the chitosan is 80-95%.
Wherein the aluminum salt is aluminum chloride; the ferric salt is polymeric ferric chloride; the rare earth material is any one of lanthanum nitrate, lanthanum chloride, lanthanum oxide, lanthanum hydroxide, cerium nitrate, cerium chloride, cerium oxide or cerium hydroxide.
The preparation method of the fluorine removal agent comprises the following steps:
(1) adding aluminum salt, ferric salt and rare earth materials in a formula amount into water, fully dissolving, and stirring at room temperature to obtain a mixed solution;
(2) slowly dripping the mixed solution into a sodium hydroxide solution, and reacting to generate a metal ion co-precipitate;
(3) separating the precipitate, cleaning, drying and grinding to obtain powder;
(4) dissolving chitosan in acetic acid, adding water (the water is added for preventing the powder from being insufficiently dissolved in the chitosan-acetic acid solution), adding the powder into the chitosan-acetic acid solution, and fully stirring to fully chelate metal ions and chitosan to obtain a mixed solution;
(5) and (3) carrying out vacuum freeze-drying on the mixed solution to obtain the powdery defluorinating agent.
In the step (2), the mass concentration of the sodium hydroxide solution is 10%, the speed of Al, Fe and La generated precipitates is inconsistent due to too low concentration of the sodium hydroxide solution, and Al, Fe and La in the co-precipitates are not uniformly distributed;
wherein, in the step (3), the drying temperature is 70-80 ℃, and the granularity of the powder is 100-200 meshes. The 100-200-mesh ultrafine powder can be fully blended with a chitosan-acetic acid solution, and the powder obtained by vacuum freeze-drying is fine and uniform. If the drying temperature is too low, the drying time is increased; if the temperature is too high, drying may be uneven, and the surface may be dried first, but the inside may contain moisture.
The method for deep fluorine removal by adopting the fluorine removal agent specifically comprises the following steps:
(1) will pass through Ca 2+ Treated fluorine-containing wastewater (F) - Less than or equal to 10mg/L) is sent to a chemical mixing pool, a deep fluorine removing agent is added into the chemical mixing pool until the mass concentration is 300-800 ppm, and the mixture is rapidly stirred (300r/min, so that the fluorine removing agent and F in the wastewater are enabled to be mixed - Fully combining), and reacting for 20-30 min;
(2) adding NaOH solution and H into the chemical mixing tank 2 SO 4 Adjusting the pH of the wastewater in the chemical mixing tank to 6.5-9.0;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide (a polymeric flocculant commonly used in the chemical mixing process, so that precipitate particles are combined to form larger alum flocs and then settle) into the flocculation tank until the mass concentration of the polyacrylamide is 3-5 ppm, stirring at a low speed (80-100 r/min, the formed flocs can be broken at a high speed), and reacting for 5-10 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, wherein the sedimentation time is 30-60 min;
(5) returning a part of sludge at the bottom of the sedimentation tank to the chemical mixing tank through a sludge return pipe, and discharging a part of sludge; wherein the sludge reflux ratio is 16-20%. If the sludge reflux ratio is too low, FeF in the returned sludge 3 、AlF 3 、LaF 3 Low content, and insufficient adsorption of newly formed FeF on the surface of crystal nuclei when the FeF is used as the crystal nuclei 3 、AlF 3 、LaF 3 So that the crystal volume is small and high-density crystallized sludge cannot be formed; if the reflux ratio is too high, the flocs newly formed in the chemical mixing tank are interfered in the sedimentation process;
(6) the effluent of the sedimentation tank enters a clean water tank, and F is in the water body in the clean water tank - In concentrations of < 1mg/L, F is usually employed on site - And (5) carrying out online monitoring by the probe.
Wherein in the step (1), Ca is added 2+ The treated fluorine-containing wastewater refers to: the first-stage defluorination effluent after calcium adding defluorination contains a small amount of CaF 2 And (4) precipitating.
Wherein, in the step (1), the concentration of the fluorine ions in the fluorine-containing wastewater is 10 mg/L-15 mg/L.
Wherein, in the step (2), the mass fraction of the polyacrylamide is 1 per mill.
According to the invention, chitosan in the defluorinating agent is used as a carrier, and abundant amino and hydroxyl functional groups on the surface of the chitosan are utilized to adsorb metal ions; acetic acid is an organic solvent of chitosan, so that Al-Fe-La/Ce co-precipitates can be fully chelated with the chitosan, and secondary pollution caused by metal ion dissolution in the defluorinating agent is greatly reduced; aluminum salt, ferric salt and rare earth elements (lanthanum and cerium) in the defluorinating agent can remove fluorinions in water through ion exchange and electrostatic attraction, and chitosan can also adsorb and remove fluorinions in water; meanwhile, rare earth elements are added into the defluorinating agent, so that the adsorption capacity is enhanced, the pH range of the defluorinating agent can be widened, and the addition of ferric salt can improve the settling property of the defluorinating agent, so that the alumen ustum is enlarged, the floc is compact, and the settling property of the sludge is improved. The method of the invention prepares the Al-Fe-La/Ce coprecipitation by titrating the mixed solution into the sodium hydroxide solution, so that the coprecipitation is fine and uniform and complete, the phenomenon of respective precipitation of metal salts is avoided, the agglomeration degree of the coprecipitation is reduced, and the uniformity of metal active sites on the chitosan is improved; meanwhile, the fully chelated metal ions and the chitosan are subjected to vacuum freeze-drying to obtain the powdery defluorinating agent, so that the chitosan can be maintainedThe integrity of the framework, and effectively reduces the loss of metal ion active sites on the chitosan and the denaturation during high-temperature calcination, and from the application aspect, the transportation cost can be reduced, and the medicament storage is convenient. The deep defluorination method adopts a sludge reflux process, part of sludge in the sedimentation tank is refluxed to the chemical mixing tank, and the defluorination agent which is not adsorbed and saturated in the sludge in the chemical mixing tank can adsorb fluorine ions in the wastewater again, so that the reutilization rate of the defluorination agent is improved; in addition, a large amount of Fe is attached to chitosan 3+ 、Al 3+ 、La 3+ And F - Combined to form FeF 3 、AlF 3 、LaF 3 The sediment is used as crystal nucleus for sedimentation of fine particles, so that the sedimentation speed of flocs is accelerated, and meanwhile, the sludge structure becomes more compact through a sludge circulating system, the content of water molecules is gradually reduced, and then high-density crystallized sludge is formed, and the volume of the high-density sludge is smaller under the condition of the same quality of the sludge.
Has the advantages that: the defluorinating agent takes chitosan as a framework, and is fully chelated in acetic acid through a co-precipitate of the chitosan and metal ions, so that the mechanical strength of the chitosan under an acidic condition is effectively improved, and meanwhile, secondary pollution caused by metal ion reverse dissolution can be effectively avoided; in addition, the coprecipitation formed by a plurality of metal ions can not only enlarge the applicable pH range of the fluorine removal agent, but also greatly improve the adsorption removal performance of fluorine ions and the settling speed of sludge flocs; the preparation method of the invention obtains various metal ion coprecipitations by a reverse coprecipitation method, the particle size of the coprecipitations is uniform, and no agglomeration or agglomeration phenomenon exists, so that the metal active sites on the chitosan are uniformly dispersed, and the adsorption performance of the defluorinating agent is improved; and finally, when the defluorinating agent is used for deep defluorination, the sludge in the sedimentation tank is refluxed according to a certain proportion, so that the density of the flocs can be effectively increased, the sedimentation speed of the sludge flocs is increased, the removal rate of fluorine ions reaches more than 95 percent, and the F-concentration is reduced to below 1.0 mg/L.
Drawings
FIG. 1 is a flow chart of a deep fluorine removal process using the fluorine removal agent of the present invention.
Detailed Description
Example 1
The defluorinating agent is prepared by the following components in percentage by mass, chitosan is used as a biomolecule framework, and an aluminum-iron-rare earth metal blend is loaded on the framework to form a chelate with a plurality of active sites; wherein, aluminum chloride: polymeric ferric sulfate: lanthanum nitrate: and (3) chitosan: the mass ratio of acetic acid is 5: 5: 20: 10: 5; wherein the deacetylation degree of chitosan is 95%.
The fluorine removal agent is prepared by the following method, and specifically comprises the following steps:
(1) mixing 5 parts of aluminum chloride, 5 parts of polymeric ferric sulfate and 20 parts of lanthanum nitrate, adding the mixture into deionized water, and fully stirring the mixture for 4 hours at 25 ℃ to obtain a mixed solution A;
(2) slowly dripping the mixed solution A into a NaOH solution with the mass concentration of 10%; reacting to generate La-Al-Fe coprecipitation;
(3) putting the mixed liquid obtained in the step (2) into a centrifuge, setting the centrifugal speed to be 10000r/min, separating after centrifugation to obtain La-Al-Fe co-precipitates, cleaning the obtained co-precipitates with deionized water to the pH value of 6.5-7.5, then putting the precipitates into a drying oven, drying at 80 ℃ to constant weight, and grinding into 200-mesh superfine powder;
(4) dissolving 10 parts of chitosan in 5 parts of acetic acid, adding deionized water, adding the powder obtained in the step (3) into the chitosan-acetic acid solution, and fully stirring for 12 hours to fully chelate metal ions with the chitosan to obtain a mixed solution B;
(5) and putting the mixed solution B into a refrigerator at the temperature of-80 ℃ for freezing and firming, then putting into a freeze dryer, starting a vacuum pump to vacuumize at the refrigeration temperature of-45 ℃, and freeze-drying by the vacuum freeze dryer to obtain the powdery defluorinating agent.
Example 2
The defluorinating agent is prepared by the following components in percentage by mass, chitosan is used as a biomolecule framework, and an aluminum-iron-rare earth metal blend is loaded on the framework to form a chelate with a plurality of active sites; wherein, aluminum chloride: polymeric ferric sulfate: lanthanum chloride: and (3) chitosan: the mass ratio of acetic acid is 10: 5: 18: 8: 4; wherein the deacetylation degree of chitosan is 95%.
The fluorine removal agent is prepared by the following method, and specifically comprises the following steps:
(1) mixing 10 parts of aluminum chloride, 5 parts of polymeric ferric sulfate and 18 parts of lanthanum chloride, adding the mixture into deionized water, and fully stirring the mixture for 6 hours at 25 ℃ to obtain a mixed solution A;
(2) slowly dripping the mixed solution A into a NaOH solution with the mass concentration of 10%; reacting to generate La-Al-Fe coprecipitation;
(3) putting the mixed liquid obtained in the step (2) into a centrifugal machine, setting the centrifugal speed to be 10000r/min, separating after centrifugation to obtain La-Al-Fe co-precipitates, cleaning the obtained co-precipitates with deionized water to the pH value of 6.5-7.5, then putting the precipitates into a drying oven, drying at 70 ℃ to constant weight, and grinding into 100-mesh superfine powder;
(4) dissolving 8 parts of chitosan in 4 parts of acetic acid, adding deionized water, adding the powder obtained in the step (3) into a chitosan-acetic acid solution, and fully stirring for 12 hours to fully chelate metal ions with the chitosan to obtain a mixed solution B;
(5) and putting the mixed solution B into a refrigerator at the temperature of-80 ℃ for freezing and firming, then putting the mixed solution B into a freeze dryer, starting a vacuum pump to pump vacuum at the refrigeration temperature of-45 ℃, and freeze-drying the mixed solution B by the vacuum freeze dryer to obtain the powdery defluorinating agent.
Example 3
The defluorinating agent is prepared by the following components in percentage by mass, chitosan is used as a biomolecule framework, and an aluminum-iron-rare earth metal blend is loaded on the framework to form a chelate with a plurality of active sites; wherein, aluminum chloride: polymeric ferric sulfate: cerium chloride: and (3) chitosan: the mass ratio of acetic acid is 10: 10: 15: 5: 3; wherein the deacetylation degree of chitosan is 95%.
The fluorine removal agent is prepared by the following method, and specifically comprises the following steps:
(1) mixing 10 parts of aluminum chloride, 10 parts of polymeric ferric sulfate and 15 parts of cerium chloride, adding the mixture into deionized water, and fully stirring the mixture for 6 hours at 25 ℃ to obtain a mixed solution A;
(2) slowly dripping the mixed solution A into a NaOH solution with the mass concentration of 10%; reacting to generate a Ce-Al-Fe coprecipitate;
(3) putting the mixed liquid obtained in the step (2) into a centrifugal machine, setting the centrifugal speed to be 10000r/min, separating after centrifugation to obtain a Ce-Al-Fe coprecipitate, cleaning the obtained coprecipitate with deionized water to the pH value of 6.5-7.5, then putting the precipitate into a drying oven, drying at 75 ℃ to constant weight, and grinding into 150-mesh ultrafine powder;
(4) dissolving 5 parts of chitosan in 3 parts of acetic acid, adding deionized water, adding the powder obtained in the step (3) into the chitosan-acetic acid solution, and fully stirring for 10 hours to fully chelate metal ions with the chitosan to obtain a mixed solution B;
(5) and putting the mixed solution B into a refrigerator at the temperature of-80 ℃ for freezing and firming, then putting the mixed solution B into a freeze dryer, starting a vacuum pump to pump vacuum at the refrigeration temperature of-45 ℃, and freeze-drying the mixed solution B by the vacuum freeze dryer to obtain the powdery defluorinating agent.
Comparative example 1
The defluorinating agent is prepared by the following components in percentage by mass, chitosan is used as a biomolecule framework, and an aluminum-iron-rare earth metal blend is loaded on the framework to form a chelate with a plurality of active sites; wherein, aluminum chloride: polymeric ferric sulfate: lanthanum nitrate: and (3) chitosan: the mass ratio of acetic acid is 5: 5: 12: 10: 5; wherein the deacetylation degree of the chitosan is 80-95%.
The fluorine removal agent is prepared by the following method, and specifically comprises the following steps:
(1) mixing 5 parts of aluminum chloride, 5 parts of polymeric ferric sulfate and 12 parts of lanthanum nitrate, adding the mixture into deionized water, and fully stirring the mixture for 4 hours at 25 ℃ to obtain a mixed solution A;
(2) slowly dripping the mixed solution A into a NaOH solution with the mass concentration of 10%; reacting to generate La-Al-Fe coprecipitation;
(3) putting the mixed solution obtained in the step (2) into a centrifugal machine, setting the centrifugal speed to 10000r/min, separating after centrifugation to obtain La-Al-Fe co-precipitate, cleaning the obtained co-precipitate with deionized water to the pH value of 6.5-7.5, then putting the precipitate into a drying oven, drying at 80 ℃ to constant weight, and grinding into 200-mesh ultrafine powder;
(4) dissolving 10 parts of chitosan in 5 parts of acetic acid, adding deionized water, adding the powder obtained in the step (3) into a chitosan-acetic acid solution, and fully stirring for 12 hours to fully chelate metal ions with the chitosan to obtain a mixed solution B;
(5) and putting the mixed solution B into a refrigerator at the temperature of-80 ℃ for freezing and firming, then putting the mixed solution B into a freeze dryer, starting a vacuum pump to pump vacuum at the refrigeration temperature of-45 ℃, and freeze-drying the mixed solution B by the vacuum freeze dryer to obtain the powdery defluorinating agent.
Comparative example 2
The defluorinating agent is prepared by the following components in percentage by mass, chitosan is used as a biomolecule framework, and an aluminum-iron-rare earth metal blend is loaded on the framework to form a chelate with a plurality of active sites; wherein, aluminum chloride: polymeric ferric sulfate: cerium chloride: and (3) chitosan: the mass ratio of acetic acid is 10: 10: 15: 5: 3; wherein the deacetylation degree of chitosan is 95%.
The fluorine removal agent is prepared by the following method, and specifically comprises the following steps:
(1) mixing 10 parts of aluminum chloride, 10 parts of polymeric ferric sulfate and 15 parts of cerium chloride, adding the mixture into deionized water, and fully stirring the mixture for 6 hours at 25 ℃ to obtain a mixed solution A;
(2) slowly dropwise adding a NaOH solution with the mass concentration of 10% into the mixed solution A; reacting to generate Ce-Al-Fe coprecipitate;
(3) putting the mixed liquid obtained in the step (2) into a centrifugal machine, setting the centrifugal speed to be 10000r/min, separating after centrifugation to obtain a Ce-Al-Fe coprecipitate, cleaning the obtained coprecipitate with deionized water to the pH value of 6.5-7.5, then putting the precipitate into a drying oven, drying at 75 ℃ to constant weight, and grinding into 150-mesh superfine powder;
(4) dissolving 5 parts of chitosan in 3 parts of acetic acid, adding deionized water, adding the powder obtained in the step (3) into a chitosan-acetic acid solution, and fully stirring for 10 hours to fully chelate metal ions with the chitosan to obtain a mixed solution B;
(5) and putting the mixed solution B into a refrigerator at the temperature of-80 ℃ for freezing and firming, then putting the mixed solution B into a freeze dryer, starting a vacuum pump to pump vacuum at the refrigeration temperature of-45 ℃, and freeze-drying the mixed solution B by the vacuum freeze dryer to obtain the powdery defluorinating agent.
The application of the fluorine removal agent of the embodiments 1-3 and the comparative examples 1-2 in the deep fluorine removal process is as follows: and constructing a reaction system, wherein the reaction system comprises a chemical mixing tank 1, a flocculation tank 2, a sedimentation tank 3 and a clean water tank 5 which are sequentially connected, and a sludge return pipe 4 is arranged between the sedimentation tank 3 and the chemical mixing tank 1.
The method for deep fluorine removal by adopting the embodiment 1 specifically comprises the following steps:
(1) will pass through Ca 2+ Treated fluorine-containing effluent (F) - Concentration of 9mg/L) is sent to a chemical mixing pool, the defluorinating agent is added until the mass concentration is 500ppm, the mixture is rapidly stirred and reacts for 30 min;
(2) adding NaOH with the mass concentration of 20% and H with the mass concentration of 20% into the chemical mixing tank 2 SO 4 The pH value of the wastewater in the adjusting tank is 7.0-9.0;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide with the mass concentration of 1 per mill into the flocculation tank until the mass concentration of the polyacrylamide is 5ppm, stirring at low speed, and reacting for 5 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, and settling for 30min in the sedimentation tank;
(5) returning sludge accounting for 20% of the total mass of the sludge at the bottom of the sedimentation tank to the chemical mixing tank through a sludge return pipe, and discharging the rest 80% of the sludge;
(6) f in wastewater after deep defluorination - The content is less than 1mg/L, can reach the discharge standard, and is discharged after being stored in a clean water tank. The method for deep fluorine removal by adopting the embodiment 2 specifically comprises the following steps:
(1) will pass through Ca 2+ Treated fluorine-containing effluent (F) - Concentration of 8mg/L) is sent to a chemical mixing pool, the defluorinating agent is added until the mass concentration is 800ppm, the mixture is rapidly stirred and reacts for 30 min;
(2) adding NaOH with the mass concentration of 20% and H with the mass concentration of 20% into the chemical mixing tank 2 SO 4 Regulating tankThe pH value of the medium wastewater is 7.0-9.0;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide with the mass concentration of 1 per mill to the flocculation tank until the mass concentration is 5ppm, stirring at low speed, and reacting for 5 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, and settling for 30min in the sedimentation tank;
(5) returning sludge accounting for 20 percent of the total mass of the sludge at the bottom of the sedimentation tank to the chemical mixing tank through a sludge return pipe, and discharging the rest 80 percent of sludge;
(6) f in wastewater after deep defluorination - The content is less than 1mg/L, can reach the discharge standard, and is discharged after being stored in a clean water tank. The method for deep fluorine removal in the embodiment 3 specifically comprises the following steps:
(1) will pass through Ca 2+ Treated fluorine-containing effluent (F) - Concentration of 10mg/L) is sent to a chemical mixing pool, the defluorinating agent is added until the mass concentration is 300ppm, the mixture is rapidly stirred and reacts for 30 min;
(2) NaOH with the mass concentration of 20 percent and H with the mass concentration of 20 percent are added into the chemical mixing tank 2 SO 4 The pH value of the wastewater in the adjusting tank is 7.0-9.0;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide with the mass concentration of 1 per mill to the flocculation tank until the mass concentration is 5ppm, stirring at low speed, and reacting for 5 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, and settling for 30min in the sedimentation tank;
(5) returning sludge accounting for 20% of the total mass of the sludge at the bottom of the sedimentation tank to the chemical mixing tank through a sludge return pipe, and discharging the rest 80% of the sludge;
(6) f in wastewater after deep defluorination - The content is less than 1mg/L, can reach the discharge standard, and is discharged after being stored in a clean water tank. The method for deeply removing fluorine by adopting the comparative example 1 specifically comprises the following steps:
(1) will pass through Ca 2+ Treated fluorine-containing effluent (F) - Concentration of 10mg/L) is sent to a chemical mixing pool, the defluorinating agent is added until the mass concentration is 500ppm, the rapid stirring is carried out, and the reaction is carried out for 30 min;
(2) adding the mass concentration into the chemical mixing tankNaOH with the concentration of 20 percent and H with the mass concentration of 20 percent 2 SO 4 The pH value of the wastewater in the adjusting tank is 7.0-9.0;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide with the mass concentration of 1 per mill to the flocculation tank until the mass concentration is 5ppm, stirring at low speed, and reacting for 5 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, and settling for 30min in the sedimentation tank;
(5) returning sludge accounting for 20 percent of the total mass of the sludge at the bottom of the sedimentation tank to the chemical mixing tank through a sludge return pipe, and discharging the rest 80 percent of sludge;
(6) f in wastewater after deep defluorination - The content is 3-5 mg/L, which is 1ppm higher than the emission standard. This is because the rare earth material addition ratio in comparative example 1 is small, resulting in the rare earth material to F - The amount of adsorption of (3) is reduced.
The method for deeply removing fluorine by adopting the comparative example 2 (the fluorine removing agent obtained by the forward precipitation method) specifically comprises the following steps:
(1) will pass through Ca 2+ Treated fluorine-containing effluent (F) - Concentration of 10mg/L) is sent to a chemical mixing pool, the defluorinating agent is added until the mass concentration is 300ppm, the mixture is rapidly stirred and reacts for 30 min;
(2) adding NaOH with the mass concentration of 20% and H with the mass concentration of 20% into the chemical mixing tank 2 SO 4 The pH value of the wastewater in the adjusting tank is 7.0-9.0;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide with the mass concentration of 1 per mill to the flocculation tank until the mass concentration is 5ppm, stirring at low speed, and reacting for 5 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, and settling for 30min in the sedimentation tank;
(5) returning sludge accounting for 20 percent of the total mass of the sludge at the bottom of the sedimentation tank to the chemical mixing tank through a sludge return pipe, and discharging the rest 80 percent of sludge;
(6) f in wastewater after deep defluorination - The content is 3-5 mg/L, which is 1ppm higher than the emission standard. The Ce-Al-Fe copolymer obtained by the forward precipitation method is incompletely coprecipitated, and agglomeration phenomenon occurs, so that the effective component adsorbs F-The surface area is reduced and the removal effect on F-is reduced.
The method for deep fluorine removal in the embodiment 3 specifically comprises the following steps:
(1) will pass through Ca 2+ Treated fluorine-containing effluent (F) - Concentration of 10mg/L) is sent to a chemical mixing pool, the defluorinating agent is added until the mass concentration is 300ppm, the mixture is rapidly stirred and reacts for 30 min;
(2) NaOH with the mass concentration of 20 percent and H with the mass concentration of 20 percent are added into the chemical mixing tank 2 SO 4 The pH value of the wastewater in the adjusting tank is 7.0-9.0;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide with the mass concentration of 1 per mill into the flocculation tank until the mass concentration of the polyacrylamide is 5ppm, stirring at low speed, and reacting for 10 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, and settling for 30min in the sedimentation tank;
(5) discharging all sludge at the bottom of the sedimentation tank, and not performing sludge backflow;
(6) f in wastewater after deep defluorination - The content is less than 1mg/L, the discharge standard can be reached, but the sedimentation speed of the flocs is reduced, the sludge compactness is deteriorated, white flocs float on the surface of the supernatant, and inclined pipes in a sedimentation area are blocked by the flocs.
The method for deeply removing fluorine by using the common aluminum salt fluorine removing agent specifically comprises the following steps:
(1) will pass through Ca 2+ Treated fluorine-containing effluent (F) - Concentration of 10mg/L) is sent to a chemical mixing pool, the defluorinating agent is added until the mass concentration is 1200-1500 ppm, the mixture is rapidly stirred and reacts for 30 min;
(2) adding NaOH with the mass concentration of 20% and H with the mass concentration of 20% into the chemical mixing tank 2 SO 4 Adjusting the pH value of the wastewater in the tank to about 6.5;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide with the mass concentration of 1 per mill to the flocculation tank until the mass concentration is 5ppm, stirring at low speed, and reacting for 5 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, and settling for 30min in the sedimentation tank;
(5) returning sludge accounting for 20 percent of the total mass of the sludge at the bottom of the sedimentation tank to the chemical mixing tank through a sludge return pipe, and discharging the rest 80 percent of sludge;
(6) f in wastewater after deep defluorination - The content is less than 1mg/L, can reach the discharge standard, and is discharged after being stored in a clean water tank.
Because the traditional aluminum salt defluorinating agent has lighter floc and pure AlF 3 Crystals are difficult to form in a mode of induced crystallization, so that the situations that flocs float on the surface of supernate and sludge blocks an inclined pipe of a settling pond still exist in a mode of high-density sludge backflow. Meanwhile, compared with the defluorinating agent disclosed by the invention, the addition amount of the traditional aluminum salt defluorinating agent is increased by 50-87.5%, which brings the defects of large sludge amount, high maintenance cost, high effluent conductivity and the like.
Claims (10)
1. A fluorine removal agent is characterized in that: the preparation method comprises the following steps of preparing a chelate compound which takes chitosan as a biomolecule framework and is loaded with an aluminum-iron-rare earth metal blend on the framework to form a plurality of active sites according to the following mass ratio; wherein, the aluminum salt: iron salt: rare earth materials: and (3) chitosan: the mass ratio of acetic acid is 5-10: 5-10: 15-20: 5-10: 3 to 5.
2. The fluorine removing agent according to claim 1, wherein: the deacetylation degree of the chitosan is 80-95%.
3. The fluorine removing agent according to claim 1, wherein: the aluminum salt is aluminum chloride; the ferric salt is polyferric chloride; the rare earth material is any one of lanthanum nitrate, lanthanum chloride, lanthanum oxide, lanthanum hydroxide, cerium nitrate, cerium chloride, cerium oxide or cerium hydroxide.
4. The method of preparing a fluorine removing agent according to claim 1, comprising the steps of:
(1) adding aluminum salt, ferric salt and rare earth materials into water according to the formula ratio, fully dissolving, and stirring at room temperature to obtain a mixed solution;
(2) slowly dripping the mixed solution into a sodium hydroxide solution, and reacting to generate a metal ion co-precipitate;
(3) separating the precipitate, cleaning, drying and grinding to obtain powder;
(4) dissolving chitosan in acetic acid, adding water, adding the powder into a chitosan acetic acid mixed solution, and fully stirring to fully chelate metal ions with the chitosan to obtain a mixed solution;
(5) and (3) performing vacuum freeze-drying on the mixed solution to obtain the powdery defluorinating agent.
5. The method for producing a fluorine removing agent according to claim 4, wherein: in the step (2), the mass concentration of the sodium hydroxide solution is 10%.
6. The method for producing a fluorine removing agent according to claim 4, wherein: in the step (3), the drying temperature is 70-80 ℃, and the granularity of the powder is 100-200 meshes.
7. The method for deep fluorine removal by using the fluorine removal agent as claimed in claim 1, which is characterized by comprising the following steps:
(1) will pass through Ca 2+ Sending the treated fluorine-containing wastewater to a chemical mixing tank, adding a deep fluorine removal agent into the chemical mixing tank until the mass concentration of the deep fluorine removal agent is 200-500 ppm, quickly stirring, and reacting for 20-30 min;
(2) adding NaOH solution and H into the chemical mixing tank 2 SO 4 Adjusting the pH value of the wastewater in the chemical mixing tank to 6.5-9.0;
(3) sending the effluent of the chemical mixing tank to a flocculation tank, adding polyacrylamide into the flocculation tank until the mass concentration of the polyacrylamide is 3-5 ppm, stirring at a low speed, and reacting for 5-10 min;
(4) sending the effluent of the flocculation tank to a sedimentation tank, wherein the sedimentation time is 30-60 min;
(5) returning a part of sludge at the bottom of the sedimentation tank to the chemical mixing tank through a sludge return pipe, and discharging a part of sludge; wherein the sludge reflux ratio is 16-20%; the sludge reflux ratio is too low, and FeF in the returned sludge 3 、AlF 3 、LaF 3 Low content, and insufficient adsorption of newly formed FeF on the surface of crystal nuclei when the FeF is used as the crystal nuclei 3 、AlF 3 、LaF 3 So that the crystal volume is small and high-density crystallized sludge cannot be formed; if the reflux ratio is too high, the newly formed flocs in the chemical mixing tank will be disturbed in the sedimentation process. FeF formed in deep defluorination 3 、AlF 3 、LaF 3 Although the amount of the precipitate is small, the solid-liquid separation speed is high and the separation effect is good because the molecular weight is large and the precipitate is easy to settle.
(6) The effluent of the sedimentation tank enters a clean water tank, and F is in the water body in the clean water tank - The concentration of (b) is less than 1 mg/L.
8. The method of deep fluorine removal according to claim 7, wherein: in step (1), Ca is added 2+ The treated fluorine-containing wastewater refers to: and (3) first-stage defluorination effluent after calcium is added for defluorination.
9. The method of deep fluorine removal according to claim 7, wherein: in the step (1), the concentration of the fluorine ions in the fluorine-containing wastewater is 10 mg/L-15 mg/L.
10. The method of deep fluorine removal according to claim 7, wherein: in the step (2), the mass fraction of the polyacrylamide is 1 per mill.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310468954.4A CN117285178A (en) | 2022-06-15 | 2022-06-15 | Deep fluorine removal method based on fluorine removal agent |
| CN202210673977.4A CN114988547B (en) | 2022-06-15 | 2022-06-15 | Fluorine removing agent |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210673977.4A CN114988547B (en) | 2022-06-15 | 2022-06-15 | Fluorine removing agent |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310468954.4A Division CN117285178A (en) | 2022-06-15 | 2022-06-15 | Deep fluorine removal method based on fluorine removal agent |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114988547A true CN114988547A (en) | 2022-09-02 |
| CN114988547B CN114988547B (en) | 2023-05-16 |
Family
ID=83034431
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310468954.4A Pending CN117285178A (en) | 2022-06-15 | 2022-06-15 | Deep fluorine removal method based on fluorine removal agent |
| CN202210673977.4A Active CN114988547B (en) | 2022-06-15 | 2022-06-15 | Fluorine removing agent |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310468954.4A Pending CN117285178A (en) | 2022-06-15 | 2022-06-15 | Deep fluorine removal method based on fluorine removal agent |
Country Status (1)
| Country | Link |
|---|---|
| CN (2) | CN117285178A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116764610A (en) * | 2023-07-24 | 2023-09-19 | 中节能(山东)循环经济有限公司 | Water body defluorinating agent and preparation method thereof |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117534169B (en) * | 2024-01-09 | 2024-04-09 | 中国科学院合肥物质科学研究院 | Deep defluorination material and preparation method and application thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003245675A (en) * | 2002-02-26 | 2003-09-02 | National Institute Of Advanced Industrial & Technology | Fluoride-ion removing method and sludge reduction method |
| JP2003320376A (en) * | 2002-02-26 | 2003-11-11 | National Institute Of Advanced Industrial & Technology | Treatment method for fluorine-containing wastewater and chemical agent used therein |
| CN101244378A (en) * | 2008-03-13 | 2008-08-20 | 中国海洋大学 | Method for preparing defluorination with chitosan |
| CN102671633A (en) * | 2012-05-07 | 2012-09-19 | 浙江大学 | Preparation method, product and application of chitosan aluminum-iron composite adsorbent |
| CN107311277A (en) * | 2017-07-04 | 2017-11-03 | 贵州美瑞特环保科技有限公司 | It is a kind of while removing nanometer medicament and preparation method thereof of arsenic phosphorus fluorine in water removal |
| WO2018122871A1 (en) * | 2016-12-30 | 2018-07-05 | INDIAN INSTITUTE OF TECHNOLOGY MADRAS (IIT Madras) | Chitosan reinforced mixed oxyhydroxide nanocomposite for fluoride and arsenic removal from water and a device thereof |
| CN111013549A (en) * | 2019-12-26 | 2020-04-17 | 西南石油大学 | Preparation method and application of modified chitosan fluoride ion adsorbent |
| CN114477406A (en) * | 2022-03-07 | 2022-05-13 | 山东环瑞生态科技有限公司 | Solid defluorination medicament and application thereof |
-
2022
- 2022-06-15 CN CN202310468954.4A patent/CN117285178A/en active Pending
- 2022-06-15 CN CN202210673977.4A patent/CN114988547B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003245675A (en) * | 2002-02-26 | 2003-09-02 | National Institute Of Advanced Industrial & Technology | Fluoride-ion removing method and sludge reduction method |
| JP2003320376A (en) * | 2002-02-26 | 2003-11-11 | National Institute Of Advanced Industrial & Technology | Treatment method for fluorine-containing wastewater and chemical agent used therein |
| CN101244378A (en) * | 2008-03-13 | 2008-08-20 | 中国海洋大学 | Method for preparing defluorination with chitosan |
| CN102671633A (en) * | 2012-05-07 | 2012-09-19 | 浙江大学 | Preparation method, product and application of chitosan aluminum-iron composite adsorbent |
| WO2018122871A1 (en) * | 2016-12-30 | 2018-07-05 | INDIAN INSTITUTE OF TECHNOLOGY MADRAS (IIT Madras) | Chitosan reinforced mixed oxyhydroxide nanocomposite for fluoride and arsenic removal from water and a device thereof |
| CN107311277A (en) * | 2017-07-04 | 2017-11-03 | 贵州美瑞特环保科技有限公司 | It is a kind of while removing nanometer medicament and preparation method thereof of arsenic phosphorus fluorine in water removal |
| CN111013549A (en) * | 2019-12-26 | 2020-04-17 | 西南石油大学 | Preparation method and application of modified chitosan fluoride ion adsorbent |
| CN114477406A (en) * | 2022-03-07 | 2022-05-13 | 山东环瑞生态科技有限公司 | Solid defluorination medicament and application thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116764610A (en) * | 2023-07-24 | 2023-09-19 | 中节能(山东)循环经济有限公司 | Water body defluorinating agent and preparation method thereof |
| CN116764610B (en) * | 2023-07-24 | 2024-03-08 | 中节能(山东)循环经济有限公司 | Water body defluorinating agent and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114988547B (en) | 2023-05-16 |
| CN117285178A (en) | 2023-12-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114988547B (en) | Fluorine removing agent | |
| JPH09276875A (en) | Treatment of waste water | |
| CN112028200B (en) | Paint mist coagulant suitable for water-based paint and preparation method thereof | |
| CN114133007A (en) | Deep defluorination medicament and use method thereof | |
| CN111498960A (en) | Defluorination medicament and application thereof | |
| CN108117195A (en) | The waste water fluoride ion removing agent of polymetallic ore mountain and processing method | |
| CN111960645A (en) | Red mud-based dehydrating agent, preparation method thereof and dehydration method of bauxite ore washing slime | |
| CN101492192B (en) | Coagulating agent for treating wastewater containing fluorine and use process thereof | |
| JP2012157865A (en) | Method for treating fluorine-containing water | |
| CN117247092A (en) | Fluorine removing agent for fluorine-containing wastewater treatment and preparation method thereof | |
| JP4272122B2 (en) | Coagulated water treatment method and apparatus | |
| JP6731261B2 (en) | Heavy metal-containing water treatment device and treatment method | |
| KR101727055B1 (en) | Polyaluminium chloride coagulants having low basicity and manufacturing method thereof | |
| CN111039375A (en) | Flocculating agent for mine beneficiation wastewater treatment and preparation method and application thereof | |
| CN111559805A (en) | Defluorination agent for pretreatment of reverse osmosis inlet water and preparation method thereof | |
| JP3325689B2 (en) | Treatment method for metal-containing wastewater | |
| CN115745113A (en) | Coking wastewater defluorinating agent and application thereof | |
| CN117088479A (en) | Rapid defluorination medicament and preparation method thereof | |
| JP3334786B2 (en) | Treatment method for wastewater containing insoluble and soluble lead, chromium and zinc | |
| JP5072780B2 (en) | Fluorine waste water treatment method using titanium oxide and metatitanic acid | |
| JP2732067B2 (en) | Coagulant for water treatment | |
| JP2004000963A (en) | Treatment method of boron-containing drainage, and medicament used for the same | |
| JP5082178B2 (en) | Fluorine-containing water treatment method | |
| JP3412641B2 (en) | Coagulation treatment of low turbidity wastewater from power plants | |
| JP7117101B2 (en) | Water treatment method and device |
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 |