CN112551652B - Surface water fluorine removal process based on carbon nano tube three-dimensional electrode - Google Patents
Surface water fluorine removal process based on carbon nano tube three-dimensional electrode Download PDFInfo
- Publication number
- CN112551652B CN112551652B CN202011443007.2A CN202011443007A CN112551652B CN 112551652 B CN112551652 B CN 112551652B CN 202011443007 A CN202011443007 A CN 202011443007A CN 112551652 B CN112551652 B CN 112551652B
- Authority
- CN
- China
- Prior art keywords
- carbon nano
- nano tube
- dimensional electrode
- fluoride
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
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
- C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
- C02F1/46104—Devices therefor; Their operating or servicing
- C02F1/46109—Electrodes
- C02F1/46114—Electrodes in particulate form or with conductive and/or non conductive particles between them
-
- 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
- C02F2101/12—Halogens or halogen-containing compounds
- C02F2101/14—Fluorine or fluorine-containing compounds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
- C02F2201/4612—Controlling or monitoring
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2201/00—Apparatus for treatment of water, waste water or sewage
- C02F2201/46—Apparatus for electrochemical processes
- C02F2201/461—Electrolysis apparatus
- C02F2201/46105—Details relating to the electrolytic devices
- C02F2201/4612—Controlling or monitoring
- C02F2201/46125—Electrical variables
- C02F2201/46135—Voltage
Abstract
The invention relates to a surface water defluorination process based on a carbon nano tube three-dimensional electrode, which mainly comprises the steps of preparing a fluoride adsorption three-dimensional electrode, modifying the surface of the carbon nano tube by using metal oxide, building a reaction device, adding a reaction reagent, electrifying the device, and carrying out surface water defluorination and fluorine ion concentration determination in an effluent sample by an electrochemical adsorption experiment. According to the invention, the metal oxide is introduced to modify the carbon nano tube, so that the specific surface area for adsorbing fluorine ions is further improved, and the fluorine ions in the water body are removed more stably; in the preparation process, ethylene glycol is used as a solvent, so that the dispersibility of the carbon nano tube is improved, the agglomeration phenomenon is effectively reduced, and metal particles are uniformly dispersed and modified on the tubular structure; the titanium mesh is used for preparing the carbon nano tube into the sheet electrode, so that the rapid recovery can be realized, secondary pollution to a water body can not be caused, the practical operation process is simple and convenient, the cost is low, and the purification treatment requirement of large-flow and large-volume fluoride-polluted surface water can be met.
Description
Technical Field
The invention belongs to the technical field of adsorbent preparation, and particularly relates to a surface water fluorine removal process based on a carbon nano tube three-dimensional electrode.
Background
Fluorine is a nonmetal element with the strongest electronegativity and the most active chemical property, can almost have an effect with all elements, and the fluorine-rich soil is deposited in natural water along with the runoff of rainwater or lake water, and fluorine-containing substances in the water increase the fluorine content in the bottom sludge through precipitation or adsorption into the sludge, so that the occurrence states are various. The safety value of the fluorine ion concentration in Chinese drinking water is 1mg/L, but the fluorine content in drinking water in many places exceeds the standard value, and along with the improvement of the national standard of surface water, the treatment of fluoride pollution, especially the fluoride pollution in the surface water, is very important.
Chemical precipitation is carried out on micro-polluted surface water by adding drugs, so that the efficiency is low, secondary pollution of a water body is easily caused, and the health of the water body is damaged. The adsorption method is simple and easy to implement, can achieve the purpose of adsorbing low-concentration pollutants, and is particularly suitable for surface water restoration projects with large water quantities. However, most of the existing effective fluoride adsorbents are small granular solids, can not be effectively separated, and can not meet the purification treatment requirements of large-flow and large-volume fluoride-polluted surface water because corresponding structures such as a filter tank need to be constructed in a matched manner.
Chinese patent CN201410032680.5 discloses a collagen-loaded hyperbranched polyester/metal ion fluoride adsorbent; chinese patent CN201910764097.6 discloses a Teff fluoride adsorbent; although the raw materials of the adsorbent are low in cost and simple to prepare, the direct addition of the adsorbent can cause water ecological damage and secondary pollution, so that the development of a fluorine removal material which is more efficient and easier to separate is needed.
The three-dimensional electrode is formed by filling granular or other clastic working electrode materials between the electrodes of the traditional two-dimensional electrolytic cell and charging the surface of the filled working materials, the three-dimensional electrode increases the electrode surface area per cell volume compared with the original flat electrode, increases the material migration speed, improves the current efficiency, and simultaneously avoids the treatment cost caused by adding a large amount of electrolyte due to the excessively low conductivity of the electrolyte, thereby becoming a high-efficiency and practical electrochemical reactor. The electrochemical adsorption changes the adsorption quantity and selectivity of the adsorption material by manipulating the interface potential, so that the electrochemical adsorption can achieve larger adsorption capacity, and has the advantages of simple and convenient operation, high efficiency, low consumption and easy desorption and regeneration.
Chinese patent CN201710050535.3 discloses an activated carbon adsorption electrochemical regeneration method for treating refractory organic wastewater, which comprises the following steps: connecting an adsorption column A, an adsorption column B and an adsorption column C in series, wherein activated carbon loaded with Fe and Mn catalysts is filled in the adsorption columns to adsorb organic matters in the concentrated water, and the produced water reaches the discharge standard of the first-level A and is directly discharged; the play water COD of every post of monitoring, after first adsorption column A pierces through, first adsorption column A goes out water COD promptly and is equivalent with the COD concentration of intaking, regenerates the active carbon in first post A, and second root adsorption column B acts as first adsorption column, and third adsorption column C acts as the second root adsorption column, and active carbon after adsorption column A loads the regeneration is as third adsorption column, carries out continuous absorption to the organic matter in the dense water. According to the method, the organic matters difficult to degrade are oxidized by electrochemical catalytic oxidation, the electrolyte is a sodium chloride solution, the problem of secondary pollution is solved, and the energy consumption is low. However, the three-dimensional electrode adopts conventional materials such as activated carbon particles and alumina particles, the adsorption capacity is limited, the recovery process is complex, and the carbon nano tube has large specific surface area and adsorption capacity as a nano material with a one-dimensional structure, so that the case of processing the carbon nano tube into the three-dimensional electrode material is not reported.
Therefore, the design of the surface water fluorine removal process based on the carbon nano tube three-dimensional electrode overcomes the defects that the fluoride in the water body can not be effectively removed, the water body is subjected to secondary pollution and the like in the prior art, and is of great importance to the technical personnel in the field.
Disclosure of Invention
In view of the above, an object of the present application is to provide a surface water fluorine removal process based on a carbon nanotube three-dimensional electrode, which overcomes the defects in the prior art that fluorides in a water body cannot be effectively removed, and secondary pollution to the water body is caused.
In order to achieve the above object, the present application provides the following technical solutions.
A preparation method of a fluoride adsorption three-dimensional electrode comprises the following steps:
s101, preparing a powdery carbon nano tube;
s102, preparing a sheet electrode by using the powdery carbon nano tube prepared in the S1;
s103, preparing the carbon nano tube three-dimensional electrode material.
Preferably, the specific operation of S101 is:
heating nitric acid to 100-110 ℃, mixing with industrial carbon nano tubes, and removing impurities;
washing the carbon nano tube by using distilled water until the pH value of the washing water is neutral;
placing in a drying oven at 80 deg.C for 12h, taking out, and grinding into powder.
Preferably, the purity of the nitric acid is 60% and the purity of the industrial-grade carbon nanotube is 98%.
Preferably, the specific operation of S102 is: mixing 0.45-0.55g of carbon nano tube with 15-25mL of ethanol, adding 0.15-0.25mL of 75% PTFE solution, carrying out ultrasonic treatment for 30min, and fixing the carbon nano tube on a 3cm x 3cm titanium net by using a roll pair machine to form a sheet electrode.
Preferably, in S103, the n sheet electrodes prepared in S102 are bound and connected by using copper wires or iron wires to prepare the carbon nanotube three-dimensional electrode material, where n is a natural number greater than 2.
Preferably, the surface of the carbon nano tube is modified by using metal oxide, so that the adsorption capacity of the three-dimensional electrode to fluoride is increased.
Preferably, the method for modifying the surface of the carbon nanotube by using the metal oxide specifically comprises the following steps:
0.6g of carbon nanotubes and 0.004 to 0.006 mol of Al2(NO3)3·9H2Dissolving O in 50mL of ethylene glycol, performing ultrasonic treatment for 1h, and performing magnetic stirring for 8-12 h; then, calcining the mixture for 2 hours at 500 ℃ in a nitrogen atmosphere of a tube furnace to prepare Al2O3The modified carbon nanotube has metal/carbon atom content of 10-15%.
Preferably, the Al2(NO3)3·9H2FeCl with molar ratio of 4:3 for O3·6H2O and FeCl2·4H2Substitution of O for Fe3O4A modified carbon nanotube;
or with Zr (NO)3)4·5H2O substitution for preparing ZrO2Modified carbon nanotubes.
Preferably, the length of the carbon nanotube is 0.5-20 μm; the grain diameters of the Al2O3, the Fe3O4 and the ZrO2 are 20-50 nm.
A surface water fluorine removal process based on a carbon nano tube three-dimensional electrode uses the fluoride adsorption three-dimensional electrode prepared by the preparation method to remove fluorine from surface water, and mainly comprises the following steps:
s201, building a reaction device and adding a reaction reagent;
s202, electrifying the device, and performing surface water defluorination in an electrochemical adsorption experiment;
s203, measuring the concentration of fluorine ions in the water sample;
the reaction device in step S201 includes: the method comprises a beaker and an electrolytic cell filled with a fluorine-containing water sample, wherein 0.002-0.004 mol/L of Na is added into the fluorine-containing water sample2SO4The electrolytic cell is characterized in that a cathode area and an anode area are isolated by a partition plate, the anode is a titanium plate, m three-dimensional electrodes are arranged in the anode area, m is a natural number greater than 2, the cathode is a stainless steel sheet, a water pump is introduced into the beaker, an opening is formed in the bottom of the anode area, a guide pipe is introduced into the opening, and the other end of the guide pipe is connected with a sample outlet beaker;
in the step S202, the voltage connected between the two pole plates of the device is 1.0-1.5V, the water pump conveys the fluorine-containing water sample to the anode area of the electrolytic cell, the flow rate is 2-3 mL/min, and the reacted water sample flows into a sample-discharging beaker from an opening at the bottom of the anode area of the electrolytic cell;
the method for measuring the fluoride ion concentration of the water sample obtained in the step S203 is ion chromatography.
The beneficial technical effects obtained by the invention are as follows:
1) the preparation method of the fluoride-adsorbing three-dimensional electrode provided by the invention adopts the carbon nano tube as a main raw material, the carbon nano tube has good chemical stability, high conductivity and large specific surface area, and can effectively adsorb fluoride ions, namely pollutants with extremely small molecular diameter, and prevent desorption.
2) The invention uses titanium net to prepare the carbon nano tube into the sheet electrode, thereby providing the practicability of the electrode in practical engineering, realizing rapid recovery and preventing the powdery carbon nano tube from being recycled.
3) According to the invention, the three-dimensional electrode is connected with the anode, so that the fluorine ions in the water body can be quickly and stably adsorbed, and after adsorption saturation, the three-dimensional electrode is connected with the cathode, so that quick desorption of the fluorine ions and quick regeneration of electrode materials can be realized, secondary pollution to the water body can not be caused, the actual operation process is simple and convenient, and the cost is low.
4) The process provided by the invention is suitable for surface water restoration projects with large water quantities, and meets the purification treatment requirements of large-flow and large-volume fluoride-polluted surface water.
5) According to the invention, the metal oxide is introduced to modify the carbon nano tube, so that the specific surface area for adsorbing fluorine ions is further improved, and the fluorine ions in the water body are removed more stably; in the process of preparing the metal modified carbon nano tube, the ethylene glycol is used as a solvent, and the ethylene glycol contains hydroxyl, so that the dispersity of the carbon nano tube can be improved, the agglomeration phenomenon can be effectively reduced, and metal particles can be more uniformly dispersed and modified on a tubular structure.
6) When the three-dimensional electrode prepared by the method is used for removing fluoride in a water body, the access voltage is 1.0-1.5V, the fluorine ion concentration of water with the fluoride content of 1.2-1.5 mg/L can be reduced to be below 0.5mg/L, the national surface water III standard is reached, and the process is also suitable for the drinking water purification treatment standard.
The foregoing description is only an overview of the technical solutions of the present application, so that the technical means of the present application can be more clearly understood and the present application can be implemented according to the content of the description, and in order to make the above and other objects, features and advantages of the present application more clearly understood, the following detailed description is made with reference to the preferred embodiments of the present application and the accompanying drawings.
The above and other objects, advantages and features of the present application will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.
FIG. 1 is a diagram of a process apparatus for a three-dimensional electrode defluorination process of carbon nanotubes;
FIG. 2 is TEM images of transmission electron microscope of carbon nanotube three-dimensional electrode materials in example 2, example 4, example 5 and example 6;
FIG. 3 is a water concentration trend chart of fluoride adsorption of carbon nanotube three-dimensional electrode materials in example 2, example 4, example 5 and example 6;
FIG. 4 is a graph of Al using different molar ratios of aluminum atoms to carbon atoms in example 82O3Modifying a trend graph of fluoride-adsorbed effluent concentration by a carbon nano tube three-dimensional electrode;
FIG. 5 is a graph showing fluoride-adsorbed water concentration trends of a three-dimensional electrode prepared in example 8 using water, ethanol, and ethylene glycol as solvents;
FIG. 6 shows the use of Al2O3XPS characterization diagrams before and after the modified carbon nano tube is adsorbed;
FIG. 7 shows recycling of Al2O3Modifying the effect graph of the carbon nano tube three-dimensional electrode;
FIG. 8 is a graph showing the tendency of the influence of chlorine ions on the effect of fluorine removal;
wherein, 1, beaker; 2. an electrolytic cell; 3. a partition plate; 4. a cathode region; 5. an anode region; 6. an anode; 7. a three-dimensional electrode; 8. a cathode; 9. a water pump; 10. an opening; and (4) taking out the sample beaker 11.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. In the following description, specific details such as specific configurations and components are provided only to help the embodiments of the present application be fully understood. Accordingly, it will be apparent to those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, descriptions of well-known functions and constructions are omitted in the embodiments for clarity and conciseness.
It should be appreciated that reference throughout this specification to "one embodiment" or "the embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrase "one embodiment" or "the present embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Further, the present application may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, B exists alone, and A and B exist at the same time, and the term "/and" is used herein to describe another association object relationship, which means that two relationships may exist, for example, A/and B, may mean: a alone, and both a and B alone, and further, the character "/" in this document generally means that the former and latter associated objects are in an "or" relationship.
The term "at least one" herein is merely an association relationship describing an associated object, and means that there may be three relationships, for example, at least one of a and B, may mean: a exists alone, A and B exist simultaneously, and B exists alone.
It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion.
Example 1
A preparation method of a fluoride adsorption three-dimensional electrode comprises the following steps:
s101, preparing a powdery carbon nano tube;
s102, preparing a sheet electrode by using the powdery carbon nano tube prepared in the S1;
s103, preparing the carbon nano tube three-dimensional electrode material.
Further, the specific operation of S101 is:
heating nitric acid to 100-110 ℃, mixing with industrial carbon nano tubes, and removing impurities;
washing the carbon nano tube by using distilled water until the pH value of the washing water is neutral;
placing in a drying oven at 80 deg.C for 12h, taking out, and grinding into powder.
Further, the purity of the nitric acid is 60%, and the purity of the industrial-grade carbon nanotube is 98%.
Further, the specific operation of S102 is: mixing 0.45-0.55g of carbon nano tube with 15-25mL of ethanol, adding 0.15-0.25mL of 75% PTFE solution, carrying out ultrasonic treatment for 30min, and fixing the carbon nano tube on a 3cm x 3cm titanium net by using a roll pair machine to form a sheet electrode.
Further, in step S103, the n sheet electrodes prepared in step S102 are bound and connected by using copper wires or iron wires to prepare the carbon nanotube three-dimensional electrode material, where n is a natural number greater than 2.
The beneficial technical effects obtained by the embodiment are as follows:
1) the preparation method of the fluoride-adsorbing three-dimensional electrode provided by this embodiment adopts the carbon nanotube as a main raw material, and the carbon nanotube has good chemical stability, high conductivity and a large specific surface area, and can effectively adsorb a fluoride ion, which is a pollutant with a very small molecular diameter, and prevent desorption.
2) The embodiment uses the titanium net to prepare the carbon nano tube into the sheet electrode, thereby providing the practicability of the carbon nano tube in practical engineering, realizing quick recovery and ensuring that the powdery carbon nano tube cannot be recycled.
Example 2
This embodiment is explained based on the above embodiment 1, and the same points as those in the above embodiment 1 are not repeated.
In the process of preparing the powdery carbon nanotube in the embodiment, nitric acid is heated to 105 ℃, and the purity of the industrial-grade carbon nanotube is 98%;
when the sheet electrode is prepared, 0.5g of powdered carbon nanotube is mixed with 20mL of ethanol, 0.2mL of 75% PTFE solution is added, and ultrasonic treatment is carried out for 30 minutes.
Example 3
This embodiment is explained based on the above embodiment 1 or 2, and the same parts as the above embodiment are not repeated.
This example mainly describes the use of Al on the surface of carbon nanotubes2O3And modifying to increase the fluoride adsorption capacity of the three-dimensional electrode.
The method for modifying the surface of the carbon nanotube by the metal oxide specifically comprises the following steps:
0.6g of carbon nanotubes and 0.004 to 0.006 mol of Al2(NO3)3·9H2Dissolving O in 50mL of ethylene glycol, performing ultrasonic treatment for 1h, and performing magnetic stirring for 8-12 h; then calcining at 500 ℃ in a tube furnace under the nitrogen atmosphereFiring for 2h to prepare Al2O3The modified carbon nanotube has metal/carbon atom content of 10-15%.
The beneficial effects obtained by the embodiment are as follows:
in the embodiment, the metal oxide is introduced to modify the carbon nanotube, so that the specific surface area for adsorbing fluorine ions is further increased, and the fluorine ions in the water body are removed more stably; in the process of preparing the metal modified carbon nano tube, the ethylene glycol is used as a solvent, and the ethylene glycol contains hydroxyl, so that the dispersity of the carbon nano tube can be improved, the agglomeration phenomenon can be effectively reduced, and metal particles can be more uniformly dispersed and modified on a tubular structure.
Example 4
This embodiment is performed based on embodiment 3, and the same points as embodiment 3 are not repeated.
In this example, 0.005mol of Al was used for the preparation of the metal oxide-modified carbon nanotubes2(NO3)3·9H2O, the time of magnetic stirring is 8 h.
Example 5
This embodiment is performed based on embodiment 3, and the same points as embodiment 3 are not repeated.
This example uses FeCl in a molar ratio of 4:33·6H2O and FeCl2·4H2Substitution of Al by O2(NO3)3·9H2O, preparation of Fe3O4The modified carbon nanotube comprises the following specific steps:
first, 0.6g of carbon nanotubes was dispersed in 20mL of ethylene glycol, and FeCl was weighed in a molar ratio of 4:33·6H2O and FeCl2·4H2And O, namely respectively adding 0.772g and 0.426g, ultrasonically mixing for 1h, magnetically stirring for 8h, and calcining the obtained solution for 2h at 500 ℃ in the atmosphere of N2 to obtain the Fe3O4 modified carbon nanotube.
Example 6
This embodiment is performed based on embodiment 3, and the same points as embodiment 3 are not repeated.
This example uses Zr (NO)3)4·5H2Substitution of Al by O2(NO3)3·9H2O, preparation of ZrO2The modified carbon nanotube comprises the following specific steps:
first, 0.6g of carbon nanotubes were dispersed in 20mL of ethylene glycol, and 0.0005 mol of Zr (NO) was added3)4·5H2O, namely 2.146g, is ultrasonically mixed for 60 minutes, then the mixture is magnetically stirred for 8 hours, and the obtained solution is calcined for 2 hours at 500 ℃ under the atmosphere of N2, so that the ZrO2 modified carbon nano tube is obtained.
Example 7
This embodiment is performed based on embodiment 1, and the same points as embodiment 1 are not repeated.
This embodiment mainly introduces a surface water fluorine removal process based on a carbon nanotube three-dimensional electrode, which uses the fluoride-adsorbing three-dimensional electrode prepared by the above preparation method to remove fluorine from surface water, as shown in fig. 1, and the main steps include:
s201, building a reaction device and adding a reaction reagent;
s202, electrifying the device, and performing surface water defluorination in an electrochemical adsorption experiment;
s203, measuring the concentration of fluorine ions in the water sample;
the reaction device in step S201 includes: a beaker 1 and an electrolytic cell 2 filled with a fluorine-containing water sample, wherein 0.002-0.004 mol/L of Na is added into the fluorine-containing water sample2SO4The electrolytic cell 2 is separated into a cathode area 4 and an anode area 5 by a partition plate 3, the anode 6 is a titanium plate, m three-dimensional electrodes 7 are arranged in the anode area 5, m is a natural number larger than 2, the cathode 8 is a stainless steel sheet, a water pump 9 is introduced into the beaker 1, an opening 10 is arranged at the bottom of the anode area 5, a conduit is introduced into the opening 10, and the other end of the conduit is connected with a sample outlet beaker 11;
in the step S202, the voltage connected between the two polar plates of the device is 1.0-1.5V, the water pump 9 is used for conveying the fluorine-containing water sample to the anode area 5 of the electrolytic cell 2, the flow rate is 2-3 mL/min, and the reacted water sample flows into the sample-discharging beaker 11 from the opening at the bottom of the anode area 5 of the electrolytic cell 2;
the method for measuring the fluoride ion concentration of the water sample obtained in the step S203 is ion chromatography.
The beneficial effects obtained by the embodiment are as follows:
1) in the embodiment, the three-dimensional electrode is connected with the anode, so that the fluorine ions in the water body can be quickly and stably adsorbed, and after adsorption saturation, the three-dimensional electrode is connected with the cathode, so that quick desorption of the fluorine ions and quick regeneration of an electrode material can be realized, secondary pollution to the water body cannot be caused, the actual operation process is simple and convenient, and the cost is low;
2) when the three-dimensional electrode prepared by the embodiment is used for removing fluoride in a water body, the access voltage is 1.0-1.5V, the fluorine ion concentration of water with the fluoride content of 1.2-1.5 mg/L can be reduced to be below 0.5mg/L, the national surface water III standard is reached, and the process is also suitable for the drinking water purification treatment standard.
Example 8
This example mainly describes the performance test results of three-dimensional electrodes prepared by controlling different conditions by the preparation method.
The defluorination performance test method is an adsorption balance method and comprises the following specific steps:
respectively placing the adsorbents prepared in the embodiments in 250ml of NaF solution and 1.5mg/L of NaF solution, oscillating at constant temperature under 303K, filtering, and testing the content of fluorine ions in the solutions at different time points; the specific test method is that 20mL of the solution after shaking is taken and rapidly filtered through a 0.45-micron filter membrane, and the concentration of the residual fluorine ions in the water body is measured by using ion chromatography and an ICS-2100 type ion chromatograph AE-205.
The test results were as follows:
1. carbon nanotubes were prepared by the methods shown in examples 2, 4, 5, 6;
FIG. 2a shows Al of example 4, as shown in FIG. 22O3TEM image of modified carbon nanotubes, FIG. 2b is example 5Fe3O4Transmission electron microscopy images of the modified carbon nanotubes; FIG. 2c is the ZrO of example 62Transmission electron microscopy images of the modified carbon nanotubes; FIG. 2d is a transmission electron micrograph of the unmodified carbon nanotube of example 2, which shows thatThe metal nanoparticles can increase the specific surface area of the carbon nanotubes and provide more adsorption sites.
FIG. 3 shows the adsorption performance obtained by modifying the carbon nanotube three-dimensional electrode without using metal and by modifying the carbon nanotube three-dimensional electrode with different metals, and it can be seen from the figure that the adsorption capacity of the carbon nanotube three-dimensional electrode can be significantly improved by metal modification, and ZrO is added2The modified carbon nanotube can obtain the best adsorption performance, Al2O3Second, Fe3O4The modified carbon nanotubes have the lowest adsorption capacity. This is because Zr element has a valence of +4 and can adsorb more fluorine ions. Considering the high price of Zr salt, Al is added2O3As the best material.
2、Al2O3The modified carbon nanotube has molar ratio of aluminum atom to carbon atom of 5%, 10% and 20%. First, 0.6g of carbon nanotubes was dispersed in 20mL of ethylene glycol, and 0.0025mol, 0.005mol and 0.01mol of Al were added thereto, respectively2(NO3)3·9H2O, i.e., 5%, 10% and 20% by atomic ratio of aluminum to carbon; ultrasonic mixing for 1h, magnetic stirring for 8h, and dissolving the obtained solution in N2Calcining for 2h at 500 ℃ in the atmosphere to obtain Al2O3A modified carbon nanotube;
as shown in FIG. 4, the optimum adsorption effect was obtained when the molar ratio of aluminum atoms to carbon atoms was 10%.
3. Preparation of Al with molar ratio of aluminum atom to carbon atom of 10% by using water, ethanol and ethylene glycol as solvents, respectively2O3Modifying the carbon nano tube;
as shown in fig. 5, the preparation of metal-modified carbon nanotubes using ethylene glycol as a solvent was most effective.
4. The carbon nanotube three-dimensional electrode after the electrochemical adsorption experiment is characterized by XPS, as shown in figure 6, the carbon nanotube three-dimensional electrode after the experiment can observe an obvious F signal, which indicates that a chemical bond is formed to stably combine fluorine ions on the carbon nanotube three-dimensional electrode.
5. The carbon nano tube three-dimensional electrode is connected with the negative electrode, as shown in figure 7, although the three-dimensional electrode has certain adsorption capacity loss, the recycling performance is good, the rapid regeneration can be realized, and the fluorine ions are reduced to below 0.8mg/L all the time.
6. FIG. 8 is a trend chart of the influence of chloride ions on the defluorination effect, and it can be seen from the chart that the presence of chloride ions has a certain influence on the adsorption of fluoride ions, but the fluoride effluent concentration can be continuously less than 1mg/l, and the fluoride effluent concentration can reach the III-class water standard.
The above description is only a preferred embodiment of the present invention, and it is not intended to limit the scope of the present invention, and various modifications and changes may be made by those skilled in the art. Variations, modifications, substitutions, integrations and parameter changes of the embodiments may be made without departing from the principle and spirit of the invention, which may be within the spirit and principle of the invention, by conventional substitution or may realize the same function.
Claims (8)
1. The preparation method of the fluoride adsorption three-dimensional electrode is characterized by comprising the following steps of:
s101, preparing a powdery carbon nano tube;
the specific operation of S101 is:
heating nitric acid to 100-110 ℃, mixing with industrial carbon nano tubes, and removing impurities;
washing the carbon nano tube by using distilled water until the pH value of the washing water is neutral;
placing in a drying oven at 80 deg.C for 12h, taking out, and grinding into powder;
the purity of the nitric acid is 60 percent, and the purity of the industrial-grade carbon nano tube is 98 percent;
s102, preparing a sheet electrode by using the powdery carbon nano tube prepared in the S1;
the specific operation of S102 is: mixing 0.45-0.55g of carbon nano tube with 15-25mL of ethanol, adding 0.15-0.25mL of 75% PTFE solution, carrying out ultrasonic treatment for 30min, and fixing the carbon nano tube on a 3cm x 3cm titanium net by using a roll pair machine to form a sheet electrode;
s103, preparing a carbon nano tube three-dimensional electrode material;
and S103, binding and connecting the n sheet electrodes prepared in S102 by using copper wires or iron wires to prepare the carbon nanotube three-dimensional electrode material, wherein n is a natural number greater than 2.
2. The method for preparing a fluoride-adsorbing three-dimensional electrode according to claim 1, wherein the surface of the carbon nanotube is modified with a metal oxide to increase the fluoride-adsorbing capacity of the three-dimensional electrode.
3. The method for preparing the fluoride-adsorbing three-dimensional electrode according to claim 2, wherein the method for modifying the surface of the carbon nanotube with the metal oxide specifically comprises:
0.6g of carbon nanotubes and 0.004 to 0.006 mol of Al2(NO3)3·9H2Dissolving O in 50mL of ethylene glycol, performing ultrasonic treatment for 1h, and performing magnetic stirring for 8-12 h; then, calcining the mixture for 2 hours at 500 ℃ in a nitrogen atmosphere of a tube furnace to prepare Al2O3The modified carbon nanotube has metal/carbon atom content of 10-15%.
4. The method of claim 3, wherein the Al is selected from the group consisting of Al, and Al2(NO3)3·9H2FeCl with molar ratio of 4:3 for O3·6H2O and FeCl2·4H2Substitution of O for Fe3O4A modified carbon nanotube;
or with Zr (NO)3)4·5H2O substitution for preparing ZrO2Modified carbon nanotubes.
5. The method for preparing a fluoride-adsorbing three-dimensional electrode according to any one of claims 1 to 4, wherein the length of the carbon nanotube is 0.5 to 20 μm.
6. The fluoride-adsorbing three-dimensional electrode as claimed in claim 3Characterized in that the Al is2O3The particle size of (A) is 20-50 nm.
7. The method of claim 4, wherein the Fe is selected from the group consisting of Fe, and Fe3O4And ZrO2The particle size of (A) is 20-50 nm.
8. A surface water defluorination process based on a carbon nano tube three-dimensional electrode, which is characterized in that the surface water defluorination is carried out by using the fluoride adsorption three-dimensional electrode prepared by the preparation method of any one of the claims 1 to 7, and the steps comprise:
s201, building a reaction device and adding a reaction reagent;
s202, electrifying the device, and performing surface water defluorination in an electrochemical adsorption experiment;
s203, measuring the concentration of fluorine ions in the water sample;
the reaction device in step S201 includes: the electrolytic cell comprises a beaker (1) and an electrolytic cell (2) filled with a fluorine-containing water sample, wherein 0.002-0.004 mol/L of Na is added into the fluorine-containing water sample2SO4The electrolytic cell (2) is separated into a cathode area (4) and an anode area (5) by a partition plate (3), the anode (6) is a titanium plate, m three-dimensional electrodes (7) are arranged in the anode area (5), m is a natural number greater than 2, the cathode (8) is a stainless steel sheet, a water pump (9) is introduced into the beaker (1), an opening (10) is arranged at the bottom of the anode area (5), a guide pipe is introduced into the opening (10), and the other end of the guide pipe is connected with a sample outlet beaker (11);
in the step S202, the voltage connected between the two pole plates of the device is 1.0-1.5V, the water pump (9) conveys the fluorine-containing water sample to the anode area (5) of the electrolytic cell (2), the flow rate is 2-3 mL/min, and the reacted water sample flows into the sample outlet beaker (11) from the bottom opening of the anode area (5) of the electrolytic cell (2);
the method for measuring the fluoride ion concentration of the water sample obtained in the step S203 is ion chromatography.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011443007.2A CN112551652B (en) | 2020-12-11 | 2020-12-11 | Surface water fluorine removal process based on carbon nano tube three-dimensional electrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011443007.2A CN112551652B (en) | 2020-12-11 | 2020-12-11 | Surface water fluorine removal process based on carbon nano tube three-dimensional electrode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112551652A CN112551652A (en) | 2021-03-26 |
| CN112551652B true CN112551652B (en) | 2022-01-14 |
Family
ID=75062705
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011443007.2A Active CN112551652B (en) | 2020-12-11 | 2020-12-11 | Surface water fluorine removal process based on carbon nano tube three-dimensional electrode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112551652B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100400714C (en) * | 2005-09-13 | 2008-07-09 | 上海大学 | Method for manufacturing carbon nanotube electrocatalytic electrode for organic waste water treatment |
| CN101764213A (en) * | 2010-01-04 | 2010-06-30 | 北京航空航天大学 | Method for preparing stannic oxide battery anode material on carbon nano tube by using electro-deposition process |
| CN102079557A (en) * | 2009-12-01 | 2011-06-01 | 北京化工大学 | Method for preparing carbon nano tube electrode |
| CN103435134A (en) * | 2013-08-23 | 2013-12-11 | 西安科技大学 | Method for improving biodegradability of semi-coking wastewater based on CNTs/Fe3O4 three-dimensional electric-Fenton |
| CN103531789A (en) * | 2012-12-27 | 2014-01-22 | 中国矿业大学 | Iron oxide-carbon nanotube ternary composite material and preparation method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1850641A (en) * | 2006-05-26 | 2006-10-25 | 上海大学 | Method for preparing carbon nano tube/tin dioxide composite electro catalytic electrode |
| CN102070230A (en) * | 2010-12-10 | 2011-05-25 | 华中师范大学 | Method for removing organic matters in water by utilizing three-dimensional electrode electro-fenton and device thereof |
| US20120186980A1 (en) * | 2011-01-26 | 2012-07-26 | Sundara Ramaprabhu | Methods and systems for separating ions from fluids |
| CN104211138B (en) * | 2013-05-30 | 2019-04-23 | 南开大学 | A method of membrane electrode is prepared based on carbon nanotube and its removal organic polluter is removed in electrolysis |
-
2020
- 2020-12-11 CN CN202011443007.2A patent/CN112551652B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100400714C (en) * | 2005-09-13 | 2008-07-09 | 上海大学 | Method for manufacturing carbon nanotube electrocatalytic electrode for organic waste water treatment |
| CN102079557A (en) * | 2009-12-01 | 2011-06-01 | 北京化工大学 | Method for preparing carbon nano tube electrode |
| CN101764213A (en) * | 2010-01-04 | 2010-06-30 | 北京航空航天大学 | Method for preparing stannic oxide battery anode material on carbon nano tube by using electro-deposition process |
| CN103531789A (en) * | 2012-12-27 | 2014-01-22 | 中国矿业大学 | Iron oxide-carbon nanotube ternary composite material and preparation method thereof |
| CN103435134A (en) * | 2013-08-23 | 2013-12-11 | 西安科技大学 | Method for improving biodegradability of semi-coking wastewater based on CNTs/Fe3O4 three-dimensional electric-Fenton |
Non-Patent Citations (4)
| Title |
|---|
| Adsorption of fluoride from water by amorphous alumina supported on carbon nanotubes;Li Yan-Hui等;《Chemical Physics Letters》;20011230;第350卷;第412-416页 * |
| 三维电极电吸附动态反应器的除氟特征研究;张腾等;《环境工程学报》;20120228;第6卷(第2期);第366-372页 * |
| 张腾等.三维电极电吸附动态反应器的除氟特征研究.《环境工程学报》.2012,第6卷(第2期),第366-372页. * |
| 改性纳米级Fe3O4对地下水中氟的吸附性能研究;吴承慧等;《环境科学与技术》;20190630;第42卷(第6期);第82-88页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112551652A (en) | 2021-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wu et al. | Amidoxime-functionalized macroporous carbon self-refreshed electrode materials for rapid and high-capacity removal of heavy metal from water | |
| Liu et al. | The study of lead removal from aqueous solution using an electrochemical method with a stainless steel net electrode coated with single wall carbon nanotubes | |
| Khaydarov et al. | Water purification from metal ions using carbon nanoparticle-conjugated polymer nanocomposites | |
| US9511346B2 (en) | Adsorption of actinides in cationic form from aqueous solutions | |
| Park et al. | Sequential removal of radioactive Cs by electrochemical adsorption and desorption reaction using core-shell structured carbon nanofiber–Prussian blue composites | |
| CN105731624B (en) | A method of utilizing heterogeneous Fenton-like reaction catalytic oxidation treatment reverse osmosis concentrated water | |
| Roy et al. | Europium doped magnetic graphene oxide-MWCNT nanohybrid for estimation and removal of arsenate and arsenite from real water samples | |
| Yang et al. | Investigation of the sequestration mechanisms of Cd (II) and 1-naphthol on discharged multi-walled carbon nanotubes in aqueous environment | |
| CN108562602B (en) | Preparation method of nickel ferricyanide/reduced graphene oxide hybrid material and application of hybrid material in high-selectivity electrochemical removal of cesium ions | |
| Liu et al. | One-step phosphite removal by an electroactive CNT filter functionalized with TiO2/CeOx nanocomposites | |
| CN104069871A (en) | Pd-Fe/graphene catalyst for removing organic halogenated wastewater and preparation method of catalyst | |
| Wang et al. | Selective fluoride removal on LaHAP/3D-rGO composite electrode by capacitive deionization | |
| CN105233570B (en) | A kind of composite modified quartz sand filter media of metal oxide iron copper and its preparation method and application | |
| Wang et al. | Recovery of rare earth by electro-sorption with sodium diphenylamine sulfonate modified activated carbon electrode | |
| Wang et al. | Confined self-assembly of S, O co-doped GCN short nanotubes/EG composite towards HMIs electrochemical detection and removal | |
| Yang et al. | Capacitive deionization of high concentrations of hexavalent chromium using nickel–ferric-layered double hydroxide/molybdenum disulfide asymmetric electrode | |
| Jain et al. | Copper hexacyanoferrate/carbon nanostructure hybrids: electrochemically switched ion-exchange electrodes for the sustainable removal of cesium from water | |
| Hashemi et al. | Development of sulfurized Polythiophene-Silver Iodide-Diethyldithiocarbamate nanoflakes toward Record-High and selective absorption and detection of mercury derivatives in aquatic substrates | |
| CN112551652B (en) | Surface water fluorine removal process based on carbon nano tube three-dimensional electrode | |
| CN112645426B (en) | Modified nano ferrous sulfide composite material and preparation method and application thereof | |
| Wang et al. | Extraction of Sr2+ from aqueous solutions using an asymmetric pulsed current-assisted electrochemical method | |
| Liu et al. | Recovery and separation of uranium in a microbial fuel cell using a titanium dioxide nanotube array cathode | |
| CN102744030A (en) | Graphite oxide-containing nano-material, its preparation method, water treatment agent and its water treatment method | |
| Li et al. | Carbon cloth supported nano-Mg (OH) 2 for the enrichment and recovery of rare earth element Eu (III) from aqueous solution | |
| Liu et al. | A coupling technology of capacitive deionization and carbon-supported petal-like VS2 composite for effective and selective adsorption of lead (II) ions |
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 |