CN113213599A - Preparation and application of nitrate radical selective extension voltage capacitance deionization electrode - Google Patents
Preparation and application of nitrate radical selective extension voltage capacitance deionization electrode Download PDFInfo
- Publication number
- CN113213599A CN113213599A CN202110503314.3A CN202110503314A CN113213599A CN 113213599 A CN113213599 A CN 113213599A CN 202110503314 A CN202110503314 A CN 202110503314A CN 113213599 A CN113213599 A CN 113213599A
- Authority
- CN
- China
- Prior art keywords
- electrode
- activated carbon
- nitrate
- nitric acid
- loaded
- 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
- 238000002242 deionisation method Methods 0.000 title claims abstract description 43
- 238000002360 preparation method Methods 0.000 title claims abstract description 8
- YPJKMVATUPSWOH-UHFFFAOYSA-N nitrooxidanyl Chemical compound [O][N+]([O-])=O YPJKMVATUPSWOH-UHFFFAOYSA-N 0.000 title claims abstract description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 129
- 238000001179 sorption measurement Methods 0.000 claims abstract description 47
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 33
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 30
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 30
- 229910002651 NO3 Inorganic materials 0.000 claims abstract description 23
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims abstract description 21
- 230000003647 oxidation Effects 0.000 claims abstract description 21
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 21
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims abstract description 19
- 150000001450 anions Chemical group 0.000 claims abstract description 17
- 239000011259 mixed solution Substances 0.000 claims abstract description 17
- 125000001453 quaternary ammonium group Chemical group 0.000 claims abstract description 16
- 150000002500 ions Chemical class 0.000 claims abstract description 14
- -1 dimethyl octadecyl Chemical group 0.000 claims abstract description 13
- 238000003795 desorption Methods 0.000 claims abstract description 8
- PZJJKWKADRNWSW-UHFFFAOYSA-N trimethoxysilicon Chemical compound CO[Si](OC)OC PZJJKWKADRNWSW-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000000243 solution Substances 0.000 claims description 33
- 229910052799 carbon Inorganic materials 0.000 claims description 29
- 239000007787 solid Substances 0.000 claims description 24
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 18
- 238000003756 stirring Methods 0.000 claims description 18
- 239000008367 deionised water Substances 0.000 claims description 15
- 229910021641 deionized water Inorganic materials 0.000 claims description 15
- 239000007788 liquid Substances 0.000 claims description 13
- 238000001035 drying Methods 0.000 claims description 12
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 10
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 claims description 10
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 8
- 238000001914 filtration Methods 0.000 claims description 8
- 239000000843 powder Substances 0.000 claims description 8
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 7
- 239000003990 capacitor Substances 0.000 claims description 7
- 239000006229 carbon black Substances 0.000 claims description 7
- 239000000839 emulsion Substances 0.000 claims description 7
- 238000002156 mixing Methods 0.000 claims description 7
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 7
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 7
- 239000006228 supernatant Substances 0.000 claims description 7
- 238000007865 diluting Methods 0.000 claims description 6
- 238000012546 transfer Methods 0.000 claims description 6
- 125000000129 anionic group Chemical group 0.000 claims description 5
- WSFMFXQNYPNYGG-UHFFFAOYSA-M dimethyl-octadecyl-(3-trimethoxysilylpropyl)azanium;chloride Chemical compound [Cl-].CCCCCCCCCCCCCCCCCC[N+](C)(C)CCC[Si](OC)(OC)OC WSFMFXQNYPNYGG-UHFFFAOYSA-M 0.000 claims description 5
- 230000002572 peristaltic effect Effects 0.000 claims description 5
- 239000011780 sodium chloride Substances 0.000 claims description 5
- 235000010344 sodium nitrate Nutrition 0.000 claims description 5
- 239000004317 sodium nitrate Substances 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 238000005406 washing Methods 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 3
- 230000035484 reaction time Effects 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 125000002091 cationic group Chemical group 0.000 claims description 2
- 150000003242 quaternary ammonium salts Chemical class 0.000 claims description 2
- 238000002444 silanisation Methods 0.000 claims description 2
- 238000003825 pressing Methods 0.000 claims 2
- 238000010438 heat treatment Methods 0.000 claims 1
- 238000000034 method Methods 0.000 abstract description 10
- 150000001768 cations Chemical group 0.000 abstract description 6
- 238000005265 energy consumption Methods 0.000 abstract description 6
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 abstract description 5
- 238000005516 engineering process Methods 0.000 description 14
- 239000000463 material Substances 0.000 description 6
- 238000011160 research Methods 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000010865 sewage Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000010612 desalination reaction Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229910014571 C—O—Si Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 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 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000008233 hard water Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical class C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 239000003607 modifier Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 125000004079 stearyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 238000012360 testing method 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
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
- C02F1/4691—Capacitive deionisation
-
- 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
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
-
- 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
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
- C02F2001/46133—Electrodes characterised by the material
-
- 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
- C02F2101/16—Nitrogen compounds, e.g. ammonia
- C02F2101/163—Nitrates
-
- 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
- C02F2101/30—Organic compounds
- C02F2101/38—Organic compounds containing nitrogen
-
- 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
- Y02W10/10—Biological treatment of water, waste water, or sewage
Abstract
The invention relates to preparation and application of a nitrate radical selective extended voltage capacitance deionization electrode, and belongs to the technical field of water treatment and resource utilization. An extended voltage capacitance deionization device of an activated carbon electrode loaded with covalent bond type dimethyl octadecyl [3- (trimethoxy silicon base) propyl ] quaternary ammonium cation group and nitric acid oxidation type carboxyl anion group is adopted to selectively adsorb nitrate radicals in the mixed solution. The electrode device of the invention has greatly improved adsorption capacity, which is improved by 140 percent compared with a pure activated carbon electrode. The selective adsorption of nitrate in the mixed solution is realized, the selectivity coefficient reaches 2.7, and the selectivity coefficient of the pure activated carbon electrode is 1.0. The extended voltage capacitance deionization electrode prevents the adsorption of ions in the desorption process because the surface of the electrode is provided with anion and cation groups, and reduces the energy consumption in the adsorption process, thereby increasing the current efficiency of the electrode.
Description
Technical Field
The invention relates to preparation and application of an extended voltage capacitive deionization electrode with nitrate radical selectivity, and belongs to the technical field of water treatment and resource utilization, namely the technical field of capacitive deionization. In particular to an extended voltage capacitance deionization device of an activated carbon electrode loaded with covalent bond type dimethyl octadecyl [3- (trimethoxy silicon base) propyl ] quaternary ammonium cation group and nitric acid oxidation type carboxyl anion group, which is used for selectively adsorbing nitrate radicals in a mixed solution.
Background
The over-standard total nitrogen becomes the water environment pollution problem worldwide, and the denitrification of urban sewage is an important measure for maintaining the ecological and water safety of urban water at present. The commonly used sewage denitrification technology such as the biological denitrification technology has the defects of insufficient carbon source, large occupied area, low treatment efficiency and the like, and simultaneously, the treatment cost is high and is greatly influenced by external environmental factors, so that the development of a novel water treatment denitrification technology is urgently needed. Capacitive Deionization (CDI) is a leading technology water treatment technology, and nearly 3000 research papers on Capacitive deionization were reported in 2020, and more researchers in countries and regions are focusing on this new water treatment technology. The advantages of CDI technology are small footprint, simple equipment and low energy consumption. Because additional supporting facilities and devices are not needed, the CDI device can be miniaturized and portable, and therefore the CDI device is suitable for the area with less personnel or the field of household centralized water treatment.
Extended voltage-capacitance deionization (eV-CDI) is a new branch of CDI technology. It is to load anion and cation groups on the cathode and anode respectively and apply voltage in the adsorption process. In the adsorption process, anions move to the anode due to electrostatic acting force and are subjected to the dual actions of physical adsorption force driven by the voltage of the polar plate and exchange adsorption force driven by cation groups; cations move to the cathode due to electrostatic acting force and are subjected to the double actions of physical adsorption force driven by the voltage of the polar plate and exchange adsorption force driven by anion groups. Compared with the traditional CDI technology which only has single plate voltage driven physical adsorption force, the eV-CDI technology endows the electrode with stronger adsorption force to solution ions. In addition, because the polar plate is loaded with anion and cation groups, the ions are difficult to be adsorbed on the opposite electrode after being desorbed in the desorption process, so the charge efficiency of the electrode is improved, and the energy consumption of the electrode is reduced.
Aiming at the research of the CDI technology, the main research fields at present are the fields of seawater desalination, hard water softening, heavy metal ion removal and the like, and the research contents are mostly the influence of electrode materials, capacitance deionization devices and external parameter conditions on the desalination performance. While the development of selective adsorption technology for specific ions is still in the beginning, the selective adsorption of CDI is a difficult research point in the field, because the traditional CDI technology is a physical adsorption technology based on an electric double layer, and the physical force is difficult to distinguish different ions in a solution, the adsorption is often non-differential and non-selective. In addition, the research on removing nitrate radicals in sewage by capacitive deionization is few and few, but sewage denitrification is beneficial to solving the problem of urban water environment, can also be used for recovering nitrogen sources, promotes resource saving, and has great practical significance for establishing a 'two-type society' and finishing the 'carbon neutralization' goal.
Disclosure of Invention
In order to solve the above problems, the present invention provides an extended voltage capacitive deionization electrode having nitrate selectivity. The cathode and the anode of the electrode are respectively loaded with nitric acid oxidation type carboxyl anion groups and covalent bond type dimethyl octadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cation groups. The extended voltage capacitance deionization electrode shows high-capacity and rapid rate adsorption on nitrate in a mixed solution, and realizes high nitrate selectivity.
The electrode consists of a cathode and an anode, wherein the anode is an activated carbon electrode loaded with covalent bond type dimethyloctadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationic groups, and the cathode is an activated carbon electrode loaded with nitric acid oxidation type carboxyl anionic groups.
The preparation method of the active carbon electrode loaded with the covalent bond type dimethyloctadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationic group comprises the following steps:
(a) adding 1-3g of commercial activated carbon powder into 500mL of 300-plus-500-mL deionized water, stirring for 30-50min by using a magneton stirrer at the rotating speed of 100-30r/min, standing for 5-10min, pouring out the supernatant after solid-liquid separation, adding water to 500mL of 300-plus-500, repeating the stirring step for 3-6 times, controlling the pH of the supernatant to be about 7 and the conductivity of the effluent to be less than 10 mu s/cm, filtering the solid powder, and putting the filtered solid powder into an oven to be dried in vacuum for 4-8h at 80 ℃ to obtain the pretreated carbon.
(b) 1-2g of the pretreated carbon obtained above was placed in a beaker, and 1-10mL of dimethyloctadecyl [3- (trimethoxysilyl) propyl ] ammonium chloride solution and 40-100mL of deionized water were added. The mixture is put into a water bath kettle to be heated and stirred, the temperature is 60-100 ℃, and the stirring speed is 100-500 r/min. Stirring for 10-20min every 3-4 h, wherein the total reaction time is 24-48 h. And after the reaction is finished, filtering the obtained solid, washing the solid for 3 to 6 times by using deionized water and ethanol, and then putting the solid into a drying oven to be dried for 4 to 8 hours at the temperature of between 60 and 80 ℃ to obtain the covalent bond type dimethyloctadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationized activated carbon.
(c) Uniformly mixing the covalent bond type quaternary ammonium cationized activated carbon and the carbon black in a ratio of 5:1 to 10:1, adding a proper amount of ethanol solution, oscillating for 5-20min under an ultrasonic state, adding 0.1-0.5mg of polytetrafluoroethylene emulsion, and continuing to put into the ultrasonic to oscillate. After 20-40min the resulting solid colloidal material was pressed onto a titanium mesh. Drying in a drying oven at 80-120 deg.C for 4-8h to obtain the active carbon electrode loaded with covalent bond type dimethyl octadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cation group.
The preparation method of the active carbon electrode loaded with nitric acid oxidation type carboxyl anion groups comprises the following steps:
(A) adding 1-3g of commercial activated carbon powder into 500mL of 300-plus-500-mL deionized water, stirring for 30-50min by using a magneton stirrer at the rotation speed of 300-plus-300 r/min, standing for 5-10min, pouring out the supernatant after solid-liquid layering, adding water to 500mL of 300-plus-500, repeating the stirring step for 3-6 times, controlling the pH of the supernatant to be about 7 and the conductivity of the effluent to be less than 10 mu s/cm, filtering the solid powder, and putting the filtered solid powder into an oven to be dried in vacuum for 4-8h at the temperature of 60-100 ℃ to obtain the pretreated carbon.
(B) Diluting concentrated nitric acid (8-12mol/L) by 5-10 times by deionized water to obtain a diluted nitric acid solution. 5-10g of the pretreated carbon powder is added into the diluted nitric acid solution, and stirred at the speed of 200-500r/min for 10-30h at room temperature. And filtering and washing the obtained solid with deionized water, and drying in an oven at 80-120 ℃ for 4-10h to obtain the nitric acid oxidation type carboxyl anionized activated carbon loaded.
(C) Uniformly mixing nitric acid oxidation type carboxyl anionized activated carbon and carbon black in a ratio of 5:1 to 10:1, adding 10-30mL of ethanol solution, oscillating for 5-20min under an ultrasonic state, adding 0.1-0.5mg of polytetrafluoroethylene emulsion, and continuing to put into the ultrasonic to oscillate. After 20-40min the resulting solid colloidal material was pressed onto a titanium mesh. Drying in a drying oven at 80-120 deg.C for 4-8h to obtain the active carbon electrode loaded with nitric acid oxidation type carboxyl anion groups.
The specific surface area of the activated carbon is 1500-2/g。
The organosilicon quaternary ammonium salt is dimethyl octadecyl [3- (trimethoxysilyl) propyl ] ammonium chloride, and the organosilicon is connected with an active carbon matrix in a C-O-Si covalent bond mode and can enhance the affinity of an electrode to nitrate.
The activated carbon material contains special trimethoxy silicon groups, and cationic groups can be connected and loaded on the surface of the activated carbon through covalent bonds through a silanization reaction. The modifier has a long carbon chain of octadecyl, can obviously increase the hydrophilicity of the electrode, and enhances the adsorption effect of ions. Meanwhile, the special quaternary ammonium group is contained, the adsorption energy to nitrate is better than that to chloride ions, and the chloride ions can be selectively adsorbed to nitrate in the mixed solution.
The application of the extended voltage capacitive deionization electrode with nitrate radical selectivity is characterized by comprising the following steps:
(a) taking an activated carbon electrode loaded with covalent bond type dimethyloctadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationic group as an anode, taking an activated carbon electrode loaded with nitric acid oxidation type carboxyl anionic group as a cathode, assembling a cathode and an anode into an extended voltage capacitance deionization device, wherein the distance between the cathode plate and the anode plate is 2-10mm, the size of an electrode plate is 5 x 5-10 x 10cm, and a bottom-in and top-out circulation mode is adopted; connecting an extended voltage capacitor deionization device with a peristaltic pump and a circulating tank in series, applying a voltage of 0.4-1.2V between a cathode and an anode, wherein the flow rate of the solution is 10-100mL/min, the circulating solution adopts 100-500mL of sodium nitrate/sodium chloride mixed solution, and the concentration of the mixed solution is 5-10 mM;
(b) absorbing 0.1-0.4mL of solution by adopting a liquid transfer gun every 10-30min, diluting, detecting the concentration of nitrate and chloride ions in the circulating tank by using an ion chromatograph, and determining the adsorption capacity of the electrode; the total adsorption time is 100-360min, when the electrode reaches the adsorption balance, the reverse electrode is desorbed, the reverse voltage is 0.4-1.2V, and the desorption time is 90-270 min.
The cathode and anode electrodes are assembled into an extended voltage capacitance deionization device, and the selective adsorption of nitrate nitrogen is tested in a mixed solution. The method comprises the following steps:
(a) taking an activated carbon electrode loaded with covalent bond type dimethyloctadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationic groups as an anode, taking an activated carbon electrode loaded with nitric acid oxidation type carboxyl anionic groups as a cathode, assembling a cathode and an anode into an extended voltage capacitance deionization device, wherein the distance between the cathode plate and the anode plate is 2-10mm, the size of an electrode plate is 5 x 5-10 x 10cm, and a flow mode of downward feeding and upward discharging is adopted.
(b) The expanded voltage capacitor deionization device is connected with a peristaltic pump and a circulating tank in series, 0.4-1.2V voltage is applied between a cathode and an anode, the flow rate of the solution is 10-100mL/min, the circulating solution adopts 100-500mL sodium nitrate/sodium chloride mixed solution, and the concentration of the mixed solution is 5-10 mM.
(c) And adsorbing 0.1-0.4mL of solution by using a liquid transfer gun every 10-30min, diluting, monitoring the concentrations of nitrate and chloride ions in the effluent by using an ion chromatograph, and determining the adsorption capacity of the electrode.
(d) The total adsorption time is 100-360min, after the electrode reaches the adsorption balance, the reverse electrode is desorbed, the reverse voltage is 0.4-1.2V, the desorption time is 90-270min, a liquid transfer gun is adopted to adsorb 0.1-0.4mL of solution every 10-30min and dilute, an ion chromatograph is used to monitor the concentration of nitrate and chloride ions in the effluent, and the desorption performance of the electrode is calculated.
(e) Repeating the processes (b) - (d) to test the cycling stability capability of the electrode.
The invention has the advantages and effects that: the active carbon electrode loaded with covalent bond type dimethyl octadecyl [3- (trimethoxy silicon base) propyl ] quaternary ammonium cation group and nitric acid oxidation type carboxyl anion group is assembled into an extended voltage capacitance deionization electrode device. The adsorption capacity is greatly improved, and compared with a pure activated carbon electrode, the unit mass adsorption capacity of the extended voltage capacitance deionization electrode is 25mg/g, which is improved by 140%.
The extended voltage capacitance deionization electrode can realize the selective adsorption of nitrate in a mixed solution, the selectivity coefficient reaches 2.7, and the selectivity coefficient of a pure activated carbon electrode is 1.0.
The extended voltage capacitance deionization electrode prevents the adsorption of ions in the desorption process because the surface of the electrode is provided with anion and cation groups, and reduces the energy consumption in the adsorption process, so that the current efficiency of the electrode is increased, and compared with 55% of a pure activated carbon electrode, the extended voltage capacitance deionization electrode reaches 50%.
Drawings
FIG. 1 is a scanning electron micrograph of pure activated carbon (a) (b) and activated carbon (c) (d) loaded with a covalently bonded dimethyloctadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationic group of example 1.
FIG. 2 is a process flow diagram of the operation of the extended voltage capacitive deionization electrode apparatus of example 1. Wherein 1 is a direct current power supply, 2 is a peristaltic pump, 3 is an anode, 4 is a cathode, 5 is a hollowed silica gel gasket, 6 is a liquid transfer device, 7 is a circulating groove, and 8 is an ion chromatograph.
FIG. 3 is a graph showing the adsorption performance of the pure activated carbon electrode (a) and the extended voltage capacitance deionization electrode (b) of example 1 in a sodium chloride/sodium nitrate mixed solution.
FIG. 4 is a graph of the selectivity for nitrate and adsorption capacity at different voltages for the extended voltage capacitance deionization electrode of example 1.
Figure 5 is a plot of charge efficiency and energy consumption for the extended voltage capacitance deionization electrode of example 1 versus a pure activated carbon electrode.
Detailed Description
The following non-limiting examples are presented to enable those of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.
Example 1
(a) Adding 2g of commercial activated carbon powder into 500mL of deionized water, stirring for 35min by using a magneton stirrer at the rotating speed of 200 revolutions/min, standing for 10min, pouring out supernatant after solid and liquid are layered, adding water to 500mL, repeating the stirring step, and repeating for 5 times to obtain the pretreated carbon.
(b) 2g of the pretreated carbon obtained above was placed in a beaker, and 5mL of dimethyloctadecyl [3- (trimethoxysilyl) propyl ] ammonium chloride solution and 45mL of deionized water were added. The mixture is put into a water bath kettle to be heated and stirred, the temperature is 80 ℃, and the total reaction time is 24 hours. Obtaining the covalent bond type quaternary ammonium cationized activated carbon.
(c) 20mL of concentrated nitric acid was diluted with 180mL of deionized water to give a dilute nitric acid solution. And (3) adding 5g of pretreated carbon into a diluted nitric acid solution, and stirring at room temperature for 10-30h to obtain the nitric acid oxidation type carboxyl anionized activated carbon.
(d) Uniformly mixing covalent bond type quaternary ammonium cationized activated carbon and carbon black in a ratio of 8:1, adding a proper amount of ethanol solution, oscillating for 10min under an ultrasonic state, adding 0.2mg of polytetrafluoroethylene emulsion, and continuing to put into the ultrasonic to oscillate. The resulting solid gum-like material was pressed onto a titanium mesh. Obtaining the active carbon electrode loaded with covalent bond type dimethyl octadecyl [3- (trimethoxy silicon base) propyl ] quaternary ammonium cation group.
(e) Uniformly mixing nitric acid oxidation type carboxyl anionized activated carbon and carbon black in a ratio of 8:1, adding a proper amount of ethanol solution, oscillating for 20min under an ultrasonic state, adding 0.2mg of polytetrafluoroethylene emulsion, and continuing to put into ultrasonic to oscillate. The resulting solid gum-like material was pressed onto a titanium mesh. Obtaining the active carbon electrode loaded with nitric acid oxidation type carboxyl anion groups.
(f) Uniformly mixing the pretreated carbon and the carbon black in a ratio of 8:1, adding a proper amount of ethanol solution, oscillating for 20min under an ultrasonic state, adding 0.2mg of polytetrafluoroethylene emulsion, and continuing to put into the ultrasonic to oscillate. The resulting solid gum-like material was pressed onto a titanium mesh. Obtaining the pure active carbon electrode.
(g) An active carbon electrode loaded with covalent bond type dimethyl octadecyl [3- (trimethoxy silicon base) propyl ] quaternary ammonium cation groups is used as an anode, an active carbon electrode loaded with nitric acid oxidation type carboxyl anion groups is used as a cathode, and an extended voltage capacitance deionization device is constructed by the anode and the cathode. Similarly, two pure activated carbon electrodes were constructed as a common capacitive deionization device as a control.
(h) The space between the cathode plate and the anode plate of all the devices is 5mm, the size of the electrode plate is 5cm by 5cm, and a bottom-in and top-out circulation mode is adopted. An extended voltage capacitor deionization device is connected with a peristaltic pump and a circulating tank in series, 0.4-1.2V voltage is applied between a cathode and an anode, the flow rate of the solution is 10mL/min, 100mL of sodium nitrate/sodium chloride mixed solution is adopted as the circulating solution, and the concentration of the mixed solution is 10 mM.
(i) And adsorbing 0.4mL of solution by using a liquid transfer gun every 20min, diluting, detecting the concentrations of nitrate ions and chloride ions in the circulating tank by using an ion chromatograph, and determining the adsorption capacity of the electrode. The total adsorption time is 120min, when the electrode reaches the adsorption balance, the reverse electrode is desorbed, the reverse voltage is 0.4-1.2V, the reverse flow rate is 30mL/min, and the desorption time is 90 min.
(j) The scanning electrodes of the activated carbon in the step (a) and the covalent bond type quaternary ammonium cationized activated carbon in the step (b) are shown in figure 1, and the surface of the pure activated carbon is smooth and flat and basically has no attachments. And the surface of the covalent bond type quaternary ammonium cationized activated carbon is uneven, and obvious substance attachment signs are shown. The capacitive deionization operation is schematically shown in figure 2, and the solution is fed in and discharged out in a circulating flow mode, so that the solution is in maximum contact with the electrodes. The electrode plate is connected to a direct current power supply through a titanium wire, and the adsorption effect under different voltages is tested. Fig. 3 shows the adsorption curve, and it can be seen that the pure activated carbon electrode reached the adsorption equilibrium at 40min and showed no selective adsorption of nitrate. And the covalent bond type quaternary ammonium cationization active carbon electrode has higher adsorption capacity to nitrate. FIG. 4 shows the adsorption capacity and selectivity of the covalent bond type quaternary ammonium cationized activated carbon electrode under different voltages, and it can be seen that the selectivity is higher under low voltage, which reaches 2.7; the adsorption capacity under high voltage is larger and reaches 340 mu mol/g (25 mg/g). Fig. 5 shows that the covalently bonded quaternary ammonium cationized activated carbon electrode has higher charge efficiency and lower energy consumption than pure activated carbon, showing the superior performance of the covalently bonded quaternary ammonium cationized activated carbon electrode.
Claims (4)
1. A nitrate radical selective extension voltage capacitance deionization electrode is characterized in that: the anode of the extended voltage capacitor deionization is an activated carbon electrode loaded with covalent bond type dimethyloctadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationic group, the cathode of the extended voltage capacitor deionization is an activated carbon electrode loaded with nitric acid oxidation type carboxyl anionic group, the anode is an anode, and the cathode is a cathode, so that the extended voltage capacitor deionization device is formed together, and the selective adsorption of nitrate in a mixed solution is realized;
the preparation method of the active carbon electrode loaded with the covalent bond type dimethyl octadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationic group comprises the following steps:
(a) adding 1-3g of commercial activated carbon powder into 500mL of 300-plus-500-mL deionized water, stirring for 30-50min by using a magneton stirrer at the rotating speed of 100-30r/min, standing for 5-10min, pouring out supernatant after solid-liquid layering, adding water to 500mL of 300-plus-500, repeating the stirring step for 3-6 times, controlling the pH of the clear liquid to be about 7 and the conductivity of the effluent to be less than 10 mu s/cm, filtering the solid powder, and putting the filtered solid powder into an oven to be dried in vacuum for 4-8h at 80 ℃ to obtain pretreated carbon;
(b) putting 1-2g of the obtained pretreated carbon into a beaker, and adding 1-10mL of dimethyl octadecyl [3- (trimethoxysilyl) propyl ] ammonium chloride solution and 40-100mL of deionized water; heating and stirring the mixture in a water bath kettle at the temperature of 60-100 ℃ and the stirring speed of 100-500 r/min; stirring for 10-20min every 3-4 h, wherein the total reaction time is 24-48 h; after the reaction is finished, filtering the obtained solid, washing the solid for 3 to 6 times by deionized water and ethanol, and then putting the solid into a drying oven to be dried for 4 to 8 hours at the temperature of between 60 and 80 ℃ to obtain the active carbon loaded with the covalent bond type dimethyl octadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cation group;
(c) uniformly mixing the covalent bond type quaternary ammonium cationized activated carbon and the carbon black in a ratio of 5:1 to 10:1, adding a proper amount of ethanol solution, oscillating for 5-20min under an ultrasonic state, adding 0.1-0.5mg of polytetrafluoroethylene emulsion, and continuing to put into the ultrasonic to oscillate; pressing the obtained solid colloidal substance on a titanium mesh after 20-40 min; drying in a drying oven at 80-120 deg.C for 4-8h to obtain activated carbon electrode loaded with covalent bond type dimethyl octadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cation group;
the preparation method of the active carbon electrode loaded with nitric acid oxidation type carboxyl anion groups comprises the following steps:
(A) adding 1-3g of commercial activated carbon powder into 500mL of 300-plus-500-mL deionized water, stirring for 30-50min by using a magneton stirrer at the rotation speed of 300-plus-300 r/min, standing for 5-10min, pouring out supernatant after solid-liquid layering, adding water to 500mL of 300-plus-500, repeating the stirring step for 3-6 times, controlling the pH of the clear liquid to be about 7 and the conductivity of the effluent to be below 10 mu s/cm, filtering the solid powder, and putting the filtered solid powder into an oven to be dried for 4-8h under vacuum at the temperature of 60-100 ℃ to obtain pretreated carbon;
(B) diluting concentrated nitric acid (8-12mol/L) by 5-10 times with deionized water to obtain a diluted nitric acid solution; taking 5-10g of pretreated carbon powder, adding the pretreated carbon powder into a dilute nitric acid solution, stirring at the speed of 200-500r/min, and stirring at room temperature for 10-30 h; filtering and washing the obtained solid with deionized water, and drying in an oven at 80-120 ℃ for 4-10h to obtain the active carbon loaded with nitric acid oxidation type carboxyl anion groups;
(C) uniformly mixing nitric acid oxidation type carboxyl anionized activated carbon and carbon black in a ratio of 5:1 to 10:1, adding 10-30mL of ethanol solution, oscillating for 5-20min under an ultrasonic state, adding 0.1-0.5mg of polytetrafluoroethylene emulsion, and continuing to put into the ultrasonic to oscillate; pressing the obtained solid colloidal substance on a titanium mesh after 20-40 min; drying in a drying oven at 80-120 deg.C for 4-8h to obtain the active carbon electrode loaded with nitric acid oxidation type carboxyl anion groups.
2. According toThe nitrate selective extension voltage capacitive deionization electrode of claim 1, wherein: the specific surface area of the commercial activated carbon powder is 1500-2/g。
3. The nitrate selective extension voltage capacitive deionization electrode according to claim 1, wherein: the organosilicon quaternary ammonium salt is dimethyl octadecyl [3- (trimethoxysilyl) propyl ] ammonium chloride which contains special trimethoxysilyl, and cationic groups are connected and loaded on the surface of the activated carbon by covalent bonds through a silanization reaction.
4. Use of a nitrate selective extension voltage capacitive deionization electrode according to claim 1, comprising the steps of:
(1) taking an activated carbon electrode loaded with covalent bond type dimethyloctadecyl [3- (trimethoxysilyl) propyl ] quaternary ammonium cationic group as an anode, taking an activated carbon electrode loaded with nitric acid oxidation type carboxyl anionic group as a cathode, assembling a cathode and an anode into an extended voltage capacitance deionization device, wherein the distance between the cathode plate and the anode plate is 2-10mm, the size of an electrode plate is 5 x 5-10 x 10cm, and a bottom-in and top-out circulation mode is adopted; connecting an extended voltage capacitor deionization device with a peristaltic pump and a circulating tank in series, applying a voltage of 0.4-1.2V between a cathode and an anode, wherein the flow rate of the solution is 10-100mL/min, the circulating solution adopts 100-500mL of sodium nitrate/sodium chloride mixed solution, and the concentration of the mixed solution is 5-10 mM;
(2) absorbing 0.1-0.4mL of solution by adopting a liquid transfer gun every 10-30min, diluting, detecting the concentration of nitrate and chloride ions in the circulating tank by using an ion chromatograph, and determining the adsorption capacity of the electrode; the total adsorption time is 100-360min, when the electrode reaches the adsorption balance, the reverse electrode is desorbed, the reverse voltage is 0.4-1.2V, and the desorption time is 90-270 min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110503314.3A CN113213599B (en) | 2021-05-10 | 2021-05-10 | Preparation and application of nitrate radical selective extension voltage capacitance deionization electrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110503314.3A CN113213599B (en) | 2021-05-10 | 2021-05-10 | Preparation and application of nitrate radical selective extension voltage capacitance deionization electrode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113213599A true CN113213599A (en) | 2021-08-06 |
| CN113213599B CN113213599B (en) | 2022-08-19 |
Family
ID=77094530
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110503314.3A Expired - Fee Related CN113213599B (en) | 2021-05-10 | 2021-05-10 | Preparation and application of nitrate radical selective extension voltage capacitance deionization electrode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113213599B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4680103A (en) * | 1986-01-24 | 1987-07-14 | Epid. Inc. | Positive particles in electrophoretic display device composition |
| CN101165828A (en) * | 2007-08-29 | 2008-04-23 | 李青海 | Buckle type electrochemical capacitor and its manufacture method |
| CN105140530A (en) * | 2015-09-09 | 2015-12-09 | 武汉大学 | Composite anode of microorganism fuel battery and preparation method for composite anode |
| CN105540764A (en) * | 2015-12-12 | 2016-05-04 | 大连理工大学 | Preparation and application of electrodes of deionization module of asymmetric capacitor |
-
2021
- 2021-05-10 CN CN202110503314.3A patent/CN113213599B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4680103A (en) * | 1986-01-24 | 1987-07-14 | Epid. Inc. | Positive particles in electrophoretic display device composition |
| CN101165828A (en) * | 2007-08-29 | 2008-04-23 | 李青海 | Buckle type electrochemical capacitor and its manufacture method |
| CN105140530A (en) * | 2015-09-09 | 2015-12-09 | 武汉大学 | Composite anode of microorganism fuel battery and preparation method for composite anode |
| CN105540764A (en) * | 2015-12-12 | 2016-05-04 | 大连理工大学 | Preparation and application of electrodes of deionization module of asymmetric capacitor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113213599B (en) | 2022-08-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wu et al. | Surface-treated carbon electrodes with modified potential of zero charge for capacitive deionization | |
| Lee et al. | Electrode reactions and adsorption/desorption performance related to the applied potential in a capacitive deionization process | |
| Gan et al. | Selective removal of nitrate ion using a novel activated carbon composite carbon electrode in capacitive deionization | |
| CN107585835B (en) | Ion exchange resin-based FCDI (FCDI) device for strengthening trace ion trapping and application | |
| Min et al. | Improved capacitive deionization of sulfonated carbon/titania hybrid electrode | |
| CN105540764B (en) | A kind of the electrode preparation and application of asymmetry capacitive deionization module | |
| CN111732165B (en) | Asymmetric CDI desalination module and desalination method using same | |
| CN106379970A (en) | Capacitive deionization technology for desalting bitter salty water by lamellar metal oxide | |
| CN109179589A (en) | The preparation method of carbon coating vanadium phosphate sodium electrode material and its application in hydridization capacitive deionization technology | |
| Saeidi et al. | Controlling adsorption of perfluoroalkyl acids on activated carbon felt by means of electrical potentials | |
| CN109607711A (en) | A kind of hydridization capacitive deionization desalination module and desalination process | |
| Iftekhar et al. | Removal of Ni (II) using multi-walled carbon nanotubes electrodes: relation between operating parameters and capacitive deionization performance | |
| Wu et al. | Enhanced capacitive deionization of an integrated membrane electrode by thin layer spray-coating of ion exchange polymers on activated carbon electrode | |
| CN111655630A (en) | Integrated CDI electrode | |
| CN103979650A (en) | Method for preparing electro-adsorption component by virtue of self-assembly technology | |
| CN110357227A (en) | A kind of method of selective Electro Sorb halide ion in composite salt waste water | |
| CN102718291B (en) | Ion exchange resin modified polyvinylidene fluoride (PVDF) charcoal electrode and preparation method thereof | |
| Barcelos et al. | Efficient and stable operation of capacitive deionization assessed by electrode and membrane asymmetry | |
| CN106191439B (en) | A kind of method of extracting vanadium from stone coal pickle liquor separating-purifying vanadium | |
| CN113213599B (en) | Preparation and application of nitrate radical selective extension voltage capacitance deionization electrode | |
| CN107010701A (en) | Utilize the method for capacitive deionization technology separation and concentration pentavalent vanadium | |
| Zhao et al. | Adsorptive behavior of prepared metal-organic framework composites on phosphates in aqueous solutions | |
| CN113257586B (en) | Preparation and application method of silver-carbon composite electrode material | |
| CN104599847B (en) | A kind of composite film material with electro-chemical activity and preparation method thereof | |
| CN112978868A (en) | Cobalt-iron layered double hydroxide @ titanium carbide electrode material and preparation method and application thereof |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20220819 |