A Cs ion selective adsorption material and preparation method thereof

Abstract

The present application relates to the field of adsorption materials and relates to a method for preparing a radionuclide ion absorption material, particularly a method for preparing a novel Cs ion selective adsorption material. This method is characterized by encapsulating fine hexacyanoferrate particles with highly selective adsorption capacity for Cs ions within a spherical carbon material. This significantly improves the uniform dispersibility and hydraulic properties of the hexacyanoferrate particles, effectively and selectively adsorbing Cs ions while avoiding the significant water resistance caused by the accumulation of hexacyanoferrate particles. Furthermore, because the spherical carbon material has a hard and dense spherical shell, it completely avoids material pulverization and debris loss, demonstrating excellent adsorption performance in the treatment of Cs-containing radioactive wastewater.

Description

Technical Field

[0001] The present application belongs to the field of adsorption materials and relates to a preparation method of a radioactive nuclide ion absorption material, and in particular to a Cs ion selective adsorption material and a preparation method thereof. Background Art

[0002] The proper disposal of radioactive wastewater generated by the nuclear industry is a key aspect of nuclear safety. Researching and developing efficient and highly selective radioactive wastewater treatment technologies to minimize waste generation is a very meaningful endeavor in the nuclear industry. Common methods for treating radioactive wastewater include:

[0003] 1) Evaporation and Concentration: After the radioactive wastewater is evaporated and concentrated, the residual liquid is solidified and disposed of, and the distillate is treated with ion exchange resin before discharge. This method consumes a lot of energy, and due to the high salt content of the radioactive wastewater, it is very corrosive to the evaporation equipment.

[0004] 2) Natural aluminosilicate treatment: This method uses natural aluminosilicates with a certain ion exchange capacity, such as kaolin, rectorite, and vermiculite, to treat radioactive wastewater, aiming to immobilize radioactive nuclide ions within these materials and complete wastewater treatment. However, these materials have limited ion exchange capacity and poor selectivity for nuclide ions, resulting in large amounts of radioactive waste that require further treatment and disposal.

[0005] 3) Zeolite treatment: Natural or synthetic zeolites possess a suitable regular spatial structure, capable of adsorbing and treating radioactive nuclides. Theoretically, the exchange capacity of zeolite for Cs ions can reach 2 meq / g. However, in practice, other ions, such as potassium, strongly interfere with Cs removal, resulting in a very low adsorption capacity. Each kilogram of zeolite can only treat 10 kilograms of wastewater. Since adsorbents cannot be regenerated during radioactive wastewater treatment, the resulting large amounts of radioactive waste require further treatment and disposal.

[0006] 4) Ion Exchange Resin Treatment: Currently, the ion exchange resins used in my country's nuclear facilities to treat low- and intermediate-level radioactive waste are mostly strong acid and base types based on styrene divinylbenzene. Typically, the resin's adsorption capacity utilization rate is less than 30%. These resins lack sufficient selectivity for the radionuclides in low- and intermediate-level radioactive waste and are single-use, non-regenerated. This results in large volumes of radioactive waste resin and considerable disposal costs. Furthermore, as organic materials, these resins have poor radiation resistance, and radiation decomposition can produce methane and hydrogen, posing a significant risk to the long-term storage of radioactive waste resins.

[0007] 5) Ammonium phosphomolybdate treatment method: Ammonium phosphomolybdate for Cs +Ammonium phosphomolybdate exhibits high selectivity, but its fine crystallites prevent packed-bed operation, severely limiting its industrial application. Sun Zhaoxiang et al. prepared hybrid materials of ammonium phosphomolybdate and tetravalent metal phosphates (such as Ti, Zr, and Sb), achieving granularization of ammonium phosphomolybdate (Ion Exchange and Adsorption, 12, 44-49, 1996; Nuclear Chemistry and Radiochemistry, 21, 76-82, 1999; Journal of Beijing Normal University (Natural Science Edition), 27, 339-343, 1991). However, the introduction of relatively expensive tetravalent metals increases costs. According to a 2002 technical report on radioactive waste treatment published by the International Atomic Energy Agency, ammonium phosphomolybdate-based materials have yet to be widely used in radioactive wastewater treatment.

[0008] 6) Ferrocyanide treatment method: Ferrocyanide fixed by transition metals reacts with radioactive Cs + , has good selective absorption capacity. + When the concentration is 5 mol / L, this type of material has a strong effect on Cs + Selectivity coefficient (for Na +) reaches 1,500,000 (Nuclear Science and Engineering, 137, 206-214, 2001). However, the mass transfer conditions inside ferrocyanide particles are poor, and the adsorption capacity is often not fully utilized (Nuclear Chemistry and Radiochemistry, 23, 108-113, 2001). Loading ferrocyanide on a porous material carrier can improve the mass transfer kinetics. Mardan studied the solvent evaporation method, using pre-formed porous silica as a carrier to immobilize K2[CoFe(CN)6] (Separation and Purification Technology 16, 147-158, 1999), and the maximum loading capacity was 1.36 g-K2[CoFe(CN)6] / g-SiO2. The solvent evaporation step required repeated multiple times, which was cumbersome and consumed a large amount of organic solvent, making it unlikely to be used in practice (Talanta, 17-23, 955, 1970). Wang Qiuping et al. prepared calcium potassium ferrocyanide, zinc potassium ferrocyanide, manganese potassium ferrocyanide and other materials by coprecipitation under acidic conditions. All of them have good Cs ion adsorption capacity. However, due to the poor stability of the particles, they are easy to break and pulverize in actual operation and cannot be used for the treatment of radioactive wastewater (Ion Exchange and Adsorption, 16(3), 225-233, 2000). Terada (Talanta 1970, 17, 955-963), Konecny ​​(Radioanal. Chem., 1973, 14, 255-266) and Mandan (Sep. Purif. Technol., 1999, 16, 147-158) all reported a method of fixing potassium ferrocyanide in silica gel and then using transition metal ions to convert it into ferrocyanide absorbent. However, because the conversion reaction takes place within the pores of the silica, it is extremely slow, requires the use of a large excess of metal ions, and the composition of the conversion reaction products is difficult to control. In addition, because the conversion reaction is difficult to complete, it is impossible to prevent some potassium ferrocyanide from being leached out and lost during the ion absorption process in the silica gel.

[0009] Jiang Changyin, Song Chongli (Nuclear Chemistry and Radiochemistry 1995, 17(2), 99-104) and others creatively used the urea-formaldehyde condensation method to make TiCl4 into TiO2 balls, and then immersed the TiO2 balls in a mixture of potassium ferrocyanide (0.7M) and hydrochloric acid (1M) to obtain spherical potassium titanium ferrocyanide absorption material. As mentioned above: the specific surface area of ​​this material is not high (14m 2 / g), there are very few internal pores, so the absorption of cesium is concentrated only in a thin layer on the surface of the particles; in addition, the particle size of the material is not uniform, and some of it will break during use. Furthermore, due to the presence of urea-formaldehyde condensate inside the material, it cannot be solidified by the common heating and sintering method after cesium ion adsorption is saturated, because NO3 - When heated, the ions will oxidize the urea-formaldehyde organic matter and cause an explosion.

[0010] To address these technical challenges, the research team led by Professor Zhao Xuan of Tsinghua University evenly dispersed the synthesized potassium hexacyanoferrate cobalt nanoparticles in alkaline silica sol, added acid to the sol under vigorous stirring to de-liquidize it, and dried it to obtain a block material composed of amorphous silica and nano-potassium hexacyanoferrate cobalt. The particle diameter of the final product can be freely selected by the crushing strength. The nano-potassium hexacyanoferrate cobalt can be regarded as a nano-brick, while the amorphous silica is a nano-cement. The material is + 、Na + and K + Cs under ion interference + A good selective adsorption effect was achieved (Nuclear Technology, 2009, 165(2), 200-208). However, the problem with this material is that as the water flows, some hexacyanoferric cobalt potassium particles will inevitably fall off, causing the effluent to turn red. When treating real radioactive Cs-containing wastewater, the shed highly active hexacyanoferric cobalt potassium particles will also adsorb Cs ions, making it impossible to reduce the radioactivity of the effluent to an extremely low level.

[0011] In order to improve the problems of irregular particle morphology and poor hydraulic properties of the above materials, the team used porous spherical silica or alumina to load Ti(OH)x, and then reacted it with potassium hexacyanoferrate (II) to generate spherical porous silica or alumina-supported potassium hexacyanoferrate (titania) adsorption materials. The materials have both excellent spherical morphology and high particle strength, as well as high specific surface area and minimal intragranular diffusion. In cold tests, they achieved excellent selective adsorption of Cs ions (Journal of Inorganic Chemistry, 2008, 24(10), 1657-1663). However, the potassium hexacyanoferrate (titania) particles on the inner wall of the pores of the material had insufficient binding force with the material, resulting in a blue-green color of the effluent. In order to reduce the coloration of the effluent, the team tried various technical solutions such as silica coating, which increased the diffusion resistance of Cs ions in the particles. Moreover, in the hot test of the material, the radioactivity of the effluent could not be stably reduced to a very low level.

[0012] It can be seen that there are two difficulties that plague hexacyanoferrate materials as Cs ion adsorbents: first, the particle size of hexacyanoferrate particles themselves is too small and the hydraulic properties are poor, making them unable to be used directly; second, supported hexacyanoferrate materials often fail thermal tests due to debris shedding and discoloration.

[0013] In summary, how to give full play to the excellent selective adsorption ability of hexacyanoferrate materials for Cs ions while avoiding the hydraulic problems caused by its fine particles and overcoming the debris shedding caused by conventional granulation processes is an industry problem for which there is no mature technical solution. In order to break through this technical dilemma, the present technical solution creatively uses high-surface carbon sphere materials obtained by carbonization of spherical ion exchange resins as carriers, so that transition metal ions and soluble hexacyanoferrate undergo co-precipitation reaction inside the carbon spheres, so that the precipitated products are in situ encapsulated inside the carbon spheres, solving the problem of nano hexacyanoferrate granulation. Moreover, since the spherical carbon material inherits the complete and dense spherical shell formed by the suspension polymerization of ion exchange resins, water and Cs ions can pass through the spherical shell, but nanoparticles cannot pass through. This completely eliminates the phenomenon of debris shedding, making the material a highly efficient and selective adsorption material for Cs. + An excellent technical solution. Summary of the Invention

[0014] The purpose of this application is to provide a Cs ion selective adsorption material and a preparation method thereof.

[0015] In a first aspect, the present application provides a method for preparing a Cs ion selective adsorption material, using the following technical solution:

[0016] A method for preparing a Cs ion selective adsorption material, wherein the material carrier is a spherical carbon material obtained by carbonizing a spherical ion exchanger, and the active component is hexacyanoferrate particles loaded inside the spherical carbon material. First, non-Group IA metal ions are loaded on adsorption sites inside the spherical carbon material, and then a soluble hexacyanoferrate solution is immersed in the spherical carbon material. The non-Group IA metal ions and the soluble hexacyanoferrate undergo a co-precipitation reaction to generate hexacyanoferrate particles containing the non-Group IA metal ions, which are then in-situ fixed inside the spherical carbon material to obtain the Cs ion selective adsorption material.

[0017] In a specific embodiment, the spherical carbon material is obtained by carbonizing an acidic or basic styrene ion exchange resin, preferably a strongly acidic macroporous resin.

[0018] In a specific embodiment, the spherical carbon material is obtained by carbonizing an acidic or alkaline phenolic resin type ion exchange resin, preferably a strongly acidic macroporous resin.

[0019] In a specific embodiment, the spherical carbon material is pre-oxidized, and the surface carboxyl content thereof is 0.1 mmol / g to 5 mmol / g.

[0020] In a specific embodiment, the pre-oxidant of the spherical carbon material is one or a mixture of any of the following in any proportion: HNO3, H2O2, acidic potassium permanganate and acidic potassium dichromate.

[0021] In a specific embodiment, the non-Group IA metal ion is Ca 2+ Mg 2+ 、Sr 2+ 、Ba 2+ 、Cu 2+ 、Zn 2+ 、Co 2+ 、Ni 2+ , Pb 2+ 、Fe 3+ Cr 3+ 、La 3+ 、Ag + 、Mn 2+ 、Al 3+ Any one or any mixture of any proportions thereof, the amount of which is 0.1 to 3 times the amount of the carboxyl substance in the spherical carbon material, preferably Ba 2+ 、Cu 2+ 、Zn 2+ 、Co 2+ 、Ni 2+ , Pb 2+ 、Fe 3+ 、Mn 2+ , and its amount is preferably 0.3 to 1 times the amount of the carboxyl substance in the spherical carbon material.

[0022] In a specific embodiment, the soluble hexacyanoferrate is any one of potassium hexacyanoferrate, sodium hexacyanoferrate, and ammonium hexacyanoferrate, or a mixture of any of them in any proportion, and its amount is 0.3 to 5 times the amount of the carboxyl substance in the spherical carbon material.

[0023] In a specific embodiment, the soluble hexacyanoferrate solution that reacts with the non-Group IA metal ions already present in the carbon spheres is acidic, and its [H + ]=0.01~2mol / L, preferably 1mol / L.

[0024] In a specific embodiment, the reaction temperature of the non-Group IA metal ions inside the carbon spheres and the soluble hexacyanoferrate is 20-100 o C, reaction time 0.5~48 hr.

[0025] In a second aspect, the present application provides a Cs ion selective adsorption material prepared using the above method.

[0026] This application has the following beneficial effects:

[0027] Encapsulating fine hexacyanoferrate particles with a highly selective adsorption capacity for Cs ions within the spherical carbon material significantly improves the uniform dispersion and hydraulic properties of the hexacyanoferrate particles. While efficiently and selectively adsorbing Cs ions, it avoids the significant water resistance caused by the accumulation of hexacyanoferrate particles. Furthermore, because the spherical carbon material has a hard and dense spherical shell, it completely avoids the problems of material pulverization and debris loss, demonstrating excellent adsorption performance in the treatment of Cs-containing radioactive wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a process flow chart for preparing a Cs ion selective adsorption material provided by the present application;

[0029] Figure 2 This is a diagram of the preparation process mechanism of a Cs ion selective adsorption material provided in this application;

[0030] Figure 3 It is the surface morphology of spherical carbon material;

[0031] Figure 4 This is the internal cross-sectional morphology of the spherical carbon material after it is crushed (magnified 400 times);

[0032] Figure 5 This is the internal cross-sectional morphology of the spherical carbon material after it is crushed (magnified 40,000 times);

[0033] Figure 6 is the pore distribution curve of the spherical carbon material used in Example 1;

[0034] Figure 7 This is a low-magnification scanning electron microscope photograph (120 times magnification) of the spherical shell surface observed after the sample particles prepared in Example 1 were crushed;

[0035] Figure 8 This is a high-magnification scanning electron microscope photograph (20,000 times magnification) of the spherical shell surface observed after the sample particles prepared in Example 1 were crushed;

[0036] Figure 9 This is a low-magnification scanning electron microscope photograph (magnification 120 times) of the internal cross-section of the crushed sample prepared in Example 1;

[0037] Figure 10This is a high-magnification scanning electron microscope photograph (20,000 times magnification) of the internal cross-section of the crushed sample prepared in Example 1;

[0038] Description of reference numerals:

[0039] 1. Spherical carbon materials; 2. Spherical carbon materials with smooth and complete spherical shells; 3. Porous spherical carbon particles tightly packed inside the spherical carbon materials; 4. Porous spherical carbon particles loaded with non-Group IA metal ions inside the spherical carbon materials; 5. Porous spherical carbon particles loaded with insoluble hexacyanoferrate inside the spherical carbon materials. DETAILED DESCRIPTION

[0040] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0041] In the drawings of this application, Figure 2 1 is a spherical carbon material, and 2 is a spherical carbon material with a smooth surface and a complete spherical shell (see Figure 3 ), 3 is a densely packed porous spherical carbon particles inside the spherical carbon material (see Figure 5 The mesopores of spherical carbon materials are the intergranular pores of these porous spherical carbon particles (see Figure 5 Scanning electron microscope photo of the spherical carbon material), and the micropores of the spherical carbon material are the intragranular pores of these spherical carbon particles. 4 is a porous spherical carbon particle loaded with non-Group IA metal ions inside the spherical carbon material, and 5 is a porous spherical carbon particle loaded with insoluble hexacyanoferrate inside the spherical carbon material.

[0042] Figure 3 This is a surface morphology image of the spherical carbon material used in this technical solution. It can be seen that its surface is intact and smooth. The broken particles in the image are fragments obtained by deliberately breaking the carbon spheres in order to observe the internal structure of the spherical carbon material.

[0043] Figure 4 This is a cross-sectional morphology of the internal structure of the spherical carbon material used in this technical solution after being crushed, with a magnification of 400 times;

[0044] Figure 5 This is the internal cross-sectional morphology of the spherical carbon material used in this technical solution after being crushed. At a magnification of 40,000 times, tightly packed spherical carbon particles can be identified, with a particle size of about 100 nm. The interparticle pores between the particles are clearly visible, with a size of about 10 to 40 nm.

[0045] Figure 6This is the pore distribution curve of the spherical carbon material used in Example 1 (adsorption pore volume / pore size distribution plot characterized by the BJH method), showing an obvious dual pore size distribution;

[0046] Figure 7 This is a low-magnification scanning electron microscope photograph (magnification 120 times) of the spherical shell surface observed after the sample particles prepared in Example 1 were crushed;

[0047] Figure 8 This is a high-magnification scanning electron microscope photograph (magnification 20,000 times) of the spherical shell surface observed after the sample particles prepared in Example 1 were crushed;

[0048] Figure 9 This is a low-magnification scanning electron microscope photograph (magnification 120 times) of the internal cross-section of the crushed sample prepared in Example 1;

[0049] Figure 10 This is a high-magnification scanning electron microscope photograph (magnification 20,000 times) of the internal cross-section of the crushed sample prepared in Example 1.

[0050] The present invention first oxidizes the spherical carbon material obtained by carbonizing the spherical ion exchange resin, and the oxidant is selected from HNO3, H2O2, acidic potassium permanganate or acidic potassium dichromate to increase the carboxyl content of the spherical carbon material to 0.1~4mmol / g, and then uses excess soluble Ca 2+ Mg 2+ 、Sr 2+ 、Ba 2+ 、Cu 2+ 、Zn 2+ 、Co 2+ 、Ni 2+ , Pb 2+ 、Fe 3+ Cr 3+ 、La 3+ 、Ag + 、Mn 2 + 、Al 3+ One or any mixture of any of the ions in any proportion is fully adsorbed and fixed on the carboxyl group of the spherical carbon material, the spherical carbon material loaded with metal ions is dried, and the spherical carbon material is made to absorb an acidic soluble hexacyanoferrate (sodium hexacyanoferrate, potassium hexacyanoferrate, ammonium hexacyanoferrate or any mixture of any of them in any proportion) solution by an equal volume impregnation method, with an acidity of [H + ] = 0.01mol / L~2mol / L, the amount of soluble hexacyanoferrate is 0.3~5 times the amount of metal ions adsorbed in the spherical carbon material, after impregnation, the reaction is carried out for 0.5~48h, the reaction temperature is 20~100o The obtained product is washed thoroughly until the water is colorless and then dried to obtain the Cs ion selective adsorption material.

[0051] It should be noted that the resin carbonization process is a very mature existing technology and has long been disclosed in patents or literature, such as the Chinese patent application with patent number CN114620723A and the "Effect of Support Activation on the Etherification Activity of PW12 / Carbonized Resin Catalyst" recorded in the Journal of Liaoning Petrochemical University. Those skilled in the art can clearly understand this process based on the existing technology. Since it is not the main invention point of this article, it will not be repeated here.

[0052] Example 1

[0053] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0054] The carbon material used in this embodiment is obtained by carbonization and activation of spherical ion exchange resin, etc., and its surface morphology is as follows: Figure 3 As shown in the figure, the internal particle accumulation is as follows Figure 5 The pore distribution is shown in Figure 6 As shown, its specific surface area is 875m 2 / g, weigh 1000g of this carbon ball material, use three times the volume of concentrated nitric acid HNO3 at 50 o C for 24 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 3.5 mmol / g. 2.5 L of copper nitrate solution (molar concentration 1.4 mol / L, molar ratio of copper ion to carboxyl group 1:1) was prepared in a molar amount equal to the carboxyl content. The carbon spheres oxidized with HNO3 were immersed for 10 hours. The carbon spheres were filtered out, washed with a small amount of water, and dried. Then, a potassium hexacyanoferrate solution 0.5 times the molar amount of carboxyl groups in the carbon spheres was prepared, with an acidity [H + ] = 1 mol / L, and loaded into the pores of the carbon spheres adsorbing copper ions by the equal volume impregnation method, 80 o C for 24 hours, the carbon spheres were thoroughly washed with water until the effluent was completely colorless, and then dried to obtain a carbon sphere material loaded with potassium hexacyanoferrate copper. The loading amount of the active adsorption component potassium hexacyanoferrate copper was 17%. A low-magnification scanning electron microscope photograph of the spherical shell surface after the sphere material was broken is shown in FIG. Figure 7 As shown in (magnification 120 times), and the high magnification scanning electron microscope photo of the spherical shell surface is as follows Figure 8 As shown (magnification 20000 times), the low magnification scanning electron microscope photo of the internal cross section of the broken pellet material is as follows Figure 9 As shown (magnification 120 times), the high magnification scanning electron microscope photo of the internal cross section of the pellet material after crushing is shown in Figure 10As shown (magnification 20000 times), compared Figure 8 and Figure 10 It can be seen that the surface of the ball material is a relatively dense and flat spherical shell, while the interior is a loose and porous structure; EDX analysis shows that the atomic percentage of potassium element on the surface of the ball material is 1.78%, the atomic percentage of iron element is 0.71%, and the atomic percentage of copper element is 0.66% ( Figure 8 ), while the atomic percentage of potassium in the internal section of the ball material is 3.3%, the atomic percentage of iron is 1.54%, and the atomic percentage of copper is 1.02% ( Figure 10 ), which is significantly higher than the percentage of each element in the outer shell of the sphere. It can be seen that most of the hexacyanoferric copper potassium is sealed inside the carbon sphere, while the content of hexacyanoferric copper potassium on the surface is relatively small. Moreover, because it is fixed inside the relatively dense carbon layer of the spherical shell, it is not easy to pulverize and produce debris. The selective absorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions and K ions with concentrations of 1 mol / L, 0.5 mol / L and 0.1 mol / L respectively. The adsorption time was 12 hours. The distribution coefficient of the adsorbent was calculated according to the formula (absorbent 0.2g, absorption liquid 50mL):

[0055] Kd = ( C 0 - C 1 ) F / C 1

[0056] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0057] The Cs ion concentration in the liquid after absorption is shown in Table 1:

[0058] Table 1 Cs ion concentration in the liquid in Example 1

[0059] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 1.85 134740 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 3.33 74694 <![CDATA[Na + 1mol / L(NaCl)]]> 4.43 56108 <![CDATA[K + 0.1mol / L(KCl)]]> 8.61 28776 <![CDATA[K + 0.5mol / L(KCl)]]> 42.2 5679 <![CDATA[K + 1mol / L(KCl)]]> 103 2175

[0060] From the adsorption test results, it can be seen that H + The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K +It still shows a strong capture ability for Cs ions under the interference of , and its adsorption effect under the same conditions is significantly better than that of the potassium hexacyanoferrate titanium material reported by Tsinghua University, making it an excellent choice for treating wastewater containing radioactive Cs ions.

[0061] Example 2

[0062] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0063] The carbon material used in this embodiment is obtained by carbonizing spherical ion exchange resin, etc. The carbonization process is simple inert gas carbonization, and its specific surface area is 518m 2 / g, pore volume 0.69mL / g, average pore diameter 5.29nm, weigh 1000g of this carbon ball material, use twice the volume of H2O2 at 40 o C for 8 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 0.1 mmol / g. 2.5 L of barium nitrate solution (barium ion molar amount: carboxyl molar amount ratio 3:1) was prepared according to the molar ratio of 3 times the carboxyl content. The carbon spheres oxidized by H2O2 were immersed for 10 hours. The carbon spheres were filtered out and washed with a small amount of water and dried. Then, a sodium hexacyanoferrate solution 5 times the molar amount of carboxyl groups in the carbon spheres was prepared, with an acidity [H + ] = 0.01 mol / L, and loaded into the pores of the carbon spheres adsorbing barium ions by the equal volume impregnation method, 100 o The reaction was continued at 400 °C for 24 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless and then dried to obtain a carbon sphere material loaded with sodium barium hexacyanoferrate. The loading of sodium barium hexacyanoferrate as the active adsorption component was 4.5%. The selective adsorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 hours. The partition coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent, 50 mL of absorption solution):

[0064] Kd = ( C 0 - C 1 ) F / C 1

[0065] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L);F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0066] The Cs ion concentration in the liquid after absorption is shown in Table 2:

[0067] Table 2 Cs ion concentration in the liquid in Example 2

[0068] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 7.43 33397 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 10.2 24260 <![CDATA[Na + 1mol / L(NaCl)]]> 14.8 16641 <![CDATA[K + 0.1mol / L(KCl)]]> 13.5 18268 <![CDATA[K + 0.5mol / L(KCl)]]> 91.7 2476 <![CDATA[K + 1mol / L(KCl)]]> 192 1052

[0069] From the adsorption test results, it can be seen that H + The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K + The results show that the capture ability of Cs ions is strong under the interference of Ba. However, compared with Example 1, the adsorption effect is slightly worse because the active component loading is slightly less and the specific surface area of ​​the raw carbon ball is slightly lower. 2+ Ions have good shielding ability against the gamma rays released by radioactive Cs ions and are an excellent choice for treating wastewater containing radioactive Cs ions.

[0070] Example 3

[0071] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0072] The carbon material used in this embodiment is a carbonized activated spherical ion exchange resin, and its specific surface area is 1025m 2 / g, pore volume 0.95mL / g, average pore diameter 3.71nm, weigh 1000g of this carbon ball material, and use four times the volume of 0.25mol / L acidic K2Cr2O7 ([H + ]=0.5mol / L) at 90 o C for 24 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 5mmol / g. 2.5L of zinc chloride solution (molar ratio of zinc ion to molar ratio of carboxyl group 3:1) was prepared according to 0.1 times the molar ratio of carboxyl content. The carbon spheres oxidized with K2Cr2O7 were impregnated for 20 hours. The carbon spheres were filtered out, washed with a small amount of water, and dried. Then, an ammonium hexacyanoferrate solution (0.3 times the molar amount of carboxyl groups in the carbon spheres) with an acidity of [H + ] = 2mol / L, and loaded into the pores of the carbon spheres adsorbing zinc ions by the method of equal volume impregnation, 20 oThe reaction was continued at 40°C for 0.5 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless and then dried to obtain a carbon sphere material loaded with ammonium hexacyanoferrate zincate. The loading of ammonium hexacyanoferrate zincate as the active adsorption component was 1.31%. The selective adsorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 hours. The partition coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent, 50 mL of absorption solution):

[0073] Kd = ( C 0 - C 1 ) F / C 1

[0074] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0075] The Cs ion concentration in the liquid after absorption is shown in Table 3:

[0076] Table 3 Cs ion concentration in the liquid in Example 3

[0077] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 15.1 16306 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 23.3 10480 <![CDATA[Na + 1mol / L(NaCl)]]> 40.1 5984 <![CDATA[K + 0.1mol / L(KCl)]]> 30.2 8028 <![CDATA[K + 0.5mol / L(KCl)]]> 146 1462 <![CDATA[K + 1mol / L(KCl)]]> 233 823

[0078] From the adsorption test results, it can be seen that H + The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K + The present invention still shows a certain capture ability for Cs ions under the interference of , but compared with Example 1, the adsorption effect is slightly worse because the active component loading is too small. The reason for the low loading may also be that the ammonium ions provided by ammonium hexacyanoferrate have a certain complexing and shielding effect on zinc, resulting in insufficient reaction between ammonium hexacyanoferrate and zinc ions. In addition, the low reaction temperature and short reaction time may also be the reasons for the low loading.

[0079] Example 4

[0080] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0081] The carbon material used in this example is a carbonized activated spherical ion exchange resin, and its specific surface area is 831 m 2 / g, pore volume 0.69mL / g, average pore diameter 3.80nm, weigh 1000g of this carbon sphere material, and use five times the volume of 0.03mol / L acidic KMnO4 ([H + ]=0.5mol / L) at 70 o C for 4 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 2mmol / g. 2.5L of cobalt chloride solution (barium ion molar amount: carboxyl molar amount ratio 0.7:1) was prepared according to the molar ratio of 0.7 times the carboxyl content. The carbon spheres oxidized with KMnO4 were impregnated for 10 hours. The carbon spheres were filtered out, washed with a small amount of water, and dried. Then, a potassium hexacyanoferrate solution with an acidity of 2 times the molar amount of carboxyl groups in the carbon spheres was prepared. + ] = 1 mol / L, and loaded into the pores of the carbon spheres adsorbing cobalt ions by the method of equal volume impregnation, 100 o The reaction was continued at 400 °C for 48 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless and then dried to obtain a carbon sphere material loaded with potassium hexacyanoferrate cobalt. The loading of potassium hexacyanoferrate cobalt as the active adsorption component was 10.2%. The selective adsorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 hours. The partition coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent, 50 mL of absorption solution):

[0082] Kd = ( C 0 - C 1 ) F / C 1

[0083] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0084] The Cs ion concentration in the liquid after absorption is shown in Table 4:

[0085] Table 4 Cs ion concentration in the liquid in Example 4

[0086] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 1.02 244848 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 2.87 86858 <![CDATA[Na + 1mol / L(NaCl)]]> 3.71 67135 <![CDATA[K + 0.1mol / L(KCl)]]> 7.42 33442 <![CDATA[K + 0.5mol / L(KCl)]]> 29.6 8196 <![CDATA[K + 1mol / L(KCl)]]> 98.3 2293

[0087] From the adsorption test results, it can be seen that H + The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K + The interference of Co 2+ Ions are used as precipitants for potassium hexacyanoferrate, and the resulting potassium hexacyanoferrate cobalt exhibits good selective absorption capacity for Cs ions, making it an excellent choice for treating wastewater containing radioactive Cs ions.

[0088] Example 5

[0089] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0090] The carbon material used in this example is a carbonized activated spherical ion exchange resin, and its specific surface area is 875 m 2 / g, pore volume 0.787mL / g, average pore diameter 3.6nm, weigh 1000g of this carbon ball material, use three times the volume of concentrated nitric acid HNO3 at 40 o C for 12 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 2.5 mmol / g. 2.5 L of magnesium sulfate solution was prepared according to a molar amount twice that of the carboxyl content (the ratio of the molar amount of magnesium ions to the molar amount of carboxyl groups was 2:1). The carbon spheres oxidized with HNO3 were immersed for 10 hours. The carbon spheres were filtered out, washed with a small amount of water, and dried. Then, a potassium hexacyanoferrate solution with an acidity of 2 times that of the molar amount of carboxyl groups in the carbon spheres was prepared. + ] = 1 mol / L, and loaded into the pores of the carbon spheres adsorbing magnesium ions by the method of equal volume impregnation, 60 o The reaction was continued at 400 °C for 10 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless and then dried to obtain a carbon sphere material loaded with potassium hexacyanoferrate. The loading of potassium hexacyanoferrate as the active adsorption component was 7.31%. The selective adsorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 hours. The partition coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent, 50 mL of absorption solution):

[0091] Kd = ( C 0 - C 1 ) F / C 1

[0092] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0093] The Cs ion concentration in the liquid after absorption is shown in Table 5:

[0094] Table 5 Cs ion concentration in the liquid in Example 5

[0095] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 6.48 38330 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 9.21 26894 <![CDATA[Na + 1mol / L(NaCl)]]> 17.3 14201 <![CDATA[K + 0.1mol / L(KCl)]]> 15.4 15983 <![CDATA[K + 0.5mol / L(KCl)]]> 76.8 3005 <![CDATA[K + 1mol / L(KCl)]]> 185.5 1098

[0096] From the adsorption test results, it can be seen that H + The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K + It still shows a strong capture ability for Cs ions under the interference of . Since the raw material magnesium sulfate is cheap and the adsorption performance of the material is moderate, the material also has certain application value.

[0097] Example 6

[0098] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0099] The carbon material used in this example is a carbonized activated spherical ion exchange resin, and its specific surface area is 831 m 2 / g, pore volume 0.69mL / g, average pore diameter 3.80nm, weigh 1000g of this carbon ball material, use three times the volume of 5mol / L HNO3 at 50 o C for 7 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 2.6 mmol / g. 2.5 L of nickel chloride solution (1:1 ratio of nickel ion molar amount to carboxyl group molar amount) was prepared in an equal amount to the carboxyl content. The carbon spheres oxidized with HNO3 were immersed in it for 10 hours. The carbon spheres were filtered out, washed with a small amount of water, and dried. Then, a potassium hexacyanoferrate solution (1 times the molar amount of carboxyl groups in the carbon spheres) was prepared. The acidity [H + ] = 1 mol / L, and loaded into the pores of the carbon spheres adsorbing nickel ions by the equal volume impregnation method, 80 oThe reaction was continued at 400 °C for 24 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless and then dried to obtain a carbon sphere material loaded with potassium nickel hexacyanoferrate. The loading of potassium nickel hexacyanoferrate as the active adsorption component was 8.1%. The selective adsorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 hours. The partition coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent, 50 mL of absorption solution):

[0100] Kd = ( C 0 - C 1 ) F / C 1

[0101] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0102] The Cs ion concentration in the liquid after absorption is shown in Table 6:

[0103] Table 6 Cs ion concentration in the liquid in Example 6

[0104] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 5.98 41556 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 10.2 24260 <![CDATA[Na + 1mol / L(NaCl)]]> 19.3 12703 <![CDATA[K + 0.1mol / L(KCl)]]> 17.5 14036 <![CDATA[K + 0.5mol / L(KCl)]]> 88.6 2572 <![CDATA[K + 1mol / L(KCl)]]> 173.1 1194

[0105] From the adsorption test results, it can be seen that H + The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K + It still shows a strong capture ability for Cs ions under the interference of ions, and is an excellent choice for treating wastewater containing radioactive Cs ions.

[0106] Example 7

[0107] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0108] The carbon material used in this example is a carbonized activated spherical ion exchange resin, and its specific surface area is 831 m 2 / g, pore volume 0.69mL / g, average pore diameter 3.80nm, weigh 1000g of this carbon ball material, use three times the volume of 5mol / L HNO3 at 50 o C for 7 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 2.6 mmol / g. 2.5 L of manganese nitrate solution was prepared in an equal molar ratio to the carboxyl content (the ratio of molar amount of manganese ion to molar amount of carboxyl group was 1:1). The carbon spheres oxidized with HNO3 were immersed for 10 hours. The carbon spheres were filtered out, washed with a small amount of water, and dried. Then, a potassium hexacyanoferrate solution with an acidity of 1 times the molar amount of carboxyl group in the carbon spheres was prepared. + ] = 1 mol / L, and loaded into the pores of the carbon spheres adsorbing manganese ions by the method of equal volume impregnation, 80 o The reaction was continued at 400 °C for 24 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless and then dried to obtain a carbon sphere material loaded with potassium hexacyanoferrate manganese. The loading of potassium hexacyanoferrate manganese as the active adsorption component was 7.33%. The selective adsorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 hours. The partition coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent, 50 mL of absorption solution):

[0109] Kd = ( C 0 - C 1 ) F / C 1

[0110] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0111] The Cs ion concentration in the liquid after absorption is shown in Table 7:

[0112] Table 7 Cs ion concentration in the liquid in Example 7

[0113] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 3.46 72004 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 4.71 52829 <![CDATA[Na + 1mol / L(NaCl)]]> 6.55 37918 <![CDATA[K + 0.1mol / L(KCl)]]> 9.47 26149 <![CDATA[K + 0.5mol / L(KCl)]]> 58.1 4052 <![CDATA[K + 1mol / L(KCl)]]> 119.8 1837

[0114] From the adsorption test results, it can be seen that H +The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K + It still shows a strong capture ability for Cs ions under the interference of ions, and is an excellent choice for treating wastewater containing radioactive Cs ions.

[0115] Example 8

[0116] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0117] The carbon material used in this example is a carbonized activated spherical ion exchange resin, and its specific surface area is 831 m 2 / g, pore volume 0.69mL / g, average pore diameter 3.80nm, weigh 1000g of this carbon ball material, use three times the volume of 5mol / L HNO3 at 50 o C for 7 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 2.6 mmol / g. 2.5 L of ferric nitrate solution was prepared in an equal molar ratio to the carboxyl content (the ratio of molar amount of iron ion to molar amount of carboxyl group was 0.5:1), and the carbon spheres oxidized with HNO3 were immersed for 10 hours. The carbon spheres were filtered out, washed with a small amount of water, and dried. Then, a potassium hexacyanoferrate solution with an acidity of 1 times the molar amount of carboxyl groups in the carbon spheres was prepared. + ]=1mol / L, and loaded into the pores of the carbon spheres adsorbing iron ions by the equal volume impregnation method, 80 o The reaction was continued at 400 °C for 24 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless and then dried to obtain a carbon sphere material loaded with potassium hexacyanoferrate. The loading of potassium hexacyanoferrate as the active adsorption component was 6.81%. The selective adsorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 hours. The partition coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent, 50 mL of absorption solution):

[0118] Kd = ( C 0 - C 1 ) F / C 1

[0119] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1: ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0120] The Cs ion concentration in the liquid after absorption is shown in Table 8:

[0121] Table 8 Cs ion concentration in the liquid in Example 8

[0122] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 2.98 83642 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 5.12 48578 <![CDATA[Na + 1mol / L(NaCl)]]> 6.46 38450 <![CDATA[K + 0.1mol / L(KCl)]]> 10.5 23559 <![CDATA[K + 0.5mol / L(KCl)]]> 55.7 4238 <![CDATA[K + 1mol / L(KCl)]]> 108.9 2046

[0123] From the adsorption test results, it can be seen that H + The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K + It still shows a strong capture ability for Cs ions under the interference of ions, and is an excellent choice for treating wastewater containing radioactive Cs ions.

[0124] Example 9

[0125] This embodiment discloses a method for preparing a Cs ion selective adsorption material, which comprises the following steps:

[0126] The carbon material used in this example is a carbonized activated spherical ion exchange resin, and its specific surface area is 831 m 2 / g, pore volume 0.69mL / g, average pore diameter 3.80nm, weigh 1000g of this carbon ball material, use three times the volume of 5mol / L HNO3 at 50 o C for 7 hours, the obtained carbon spheres were washed and dried, and the surface carboxyl content was measured to be 2.6 mmol / g. 2.5 L of lanthanum nitrate solution was prepared in an equal molar ratio to the carboxyl content (the ratio of lanthanum ion molar amount to carboxyl group molar amount was 0.5:1), and the carbon spheres oxidized with HNO3 were immersed for 10 hours. The carbon spheres were filtered out, washed with a small amount of water, and dried. Then, a potassium hexacyanoferrate solution with an acidity of 1 times the molar amount of carboxyl groups in the carbon spheres was prepared. + ] = 1 mol / L, and loaded into the pores of the carbon spheres adsorbing lanthanum ions by an equal volume impregnation method, 80 oThe reaction was continued at 400 °C for 24 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless and then dried to obtain a carbon sphere material loaded with potassium lanthanum hexacyanoferrate. The loading of potassium lanthanum hexacyanoferrate as the active adsorption component was 9.12% (due to the large atomic weight of lanthanum). The selective adsorption capacity of this material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 hours. The partition coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent, 50 mL of absorption solution):

[0127] Kd = ( C 0 - C 1 ) F / C 1

[0128] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0129] The Cs ion concentration in the liquid after absorption is shown in Table 9:

[0130] Table 9 Cs ion concentration in the liquid in Example 9

[0131] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.5mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[H + 0.1mol / L (HCl)]]> <1μg / L (undetectable) >249750 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 4.26 58435 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 6.88 36087 <![CDATA[Na + 1mol / L(NaCl)]]> 7.96 31157 <![CDATA[K + 0.1mol / L(KCl)]]> 13.1 18834 <![CDATA[K + 0.5mol / L(KCl)]]> 58.4 4031 <![CDATA[K + 1mol / L(KCl)]]> 120.9 1818

[0132] From the adsorption test results, it can be seen that H + The presence of has no effect on the material's adsorption of Cs ions, which is completely incomparable to ion exchange resin materials. + and K + It still shows a strong capture ability for Cs ions under the interference of ions, and is an excellent choice for treating wastewater containing radioactive Cs ions.

[0133] Comparative Example 1

[0134] The carbon material used in this example is a carbonized activated spherical ion exchange resin, and its specific surface area is 831 m 2 / g, pore volume 0.69mL / g, average pore diameter 3.80nm, weigh 1000g of this carbon ball material, and measure its surface carboxyl content to be 0.05mmol / g, load 2.5L of 0.2mol / L copper nitrate solution into it, impregnate the carbon ball for 10hr, filter out the carbon ball, wash with a small amount of water and dry it, then take 1mol of potassium hexacyanoferrate, acidity [H + ] = 1 mol / L, and loaded into the pores of the carbon spheres adsorbing copper nitrate by the method of equal volume impregnation, 80 o C for 24 hours, the carbon balls were thoroughly washed with water until the effluent was completely colorless, and then dried to obtain a carbon ball material loaded with potassium hexacyanoferrate. The loading amount of the active adsorption component potassium hexacyanoferrate was only 0.08%. The reason is that the carbon balls have too weak a fixation ability for copper ions. After washing, the copper ions escape and too few residual copper ions remain. Therefore, the content of potassium hexacyanoferrate produced after the reaction with potassium hexacyanoferrate is too low. The selective absorption capacity of the material for Cs ions is characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions and K ions with concentrations of 1 mol / L, 0.5 mol / L and 0.1 mol / L, respectively. The adsorption time is 12 hours, and the distribution coefficient of the adsorbent is calculated according to the formula (0.2 g of absorbent, 50 mL of absorption liquid):

[0135] Kd = ( C 0 - C 1 ) F / C 1

[0136] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0137] The Cs ion concentration in the liquid after absorption is shown in Table 10:

[0138] Table 10 Cs ion concentration in the liquid in Comparative Example 1

[0139] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> 59.7 3938 <![CDATA[H + 0.5mol / L (HCl)]]> 67.3 3465 <![CDATA[H + 0.1mol / L (HCl)]]> 79.9 2879 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 87.1 2620 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 96.5 2340 <![CDATA[Na + 1mol / L(NaCl)]]> 188.7 1075 <![CDATA[K + 0.1mol / L(KCl)]]> 232.9 823 <![CDATA[K + 0.5mol / L(KCl)]]> 317.6 537 <![CDATA[K + 1mol / L(KCl)]]> 517.8 233

[0140] From the adsorption test results, it can be seen that the adsorption activity of the material for Cs ions is poor due to the low content of active components.

[0141] Comparative Example 2

[0142] The carbon material used in this example is a carbonized activated spherical ion exchange resin, and its specific surface area is 831 m 2 / g, pore volume 0.69mL / g, average pore diameter 3.80nm, weighed 1000g of this carbon ball material, measured its surface carboxyl content of 0.05mmol / g, loaded it with 2.5L of 0.2mol / L cobalt nitrate solution, impregnated the carbon ball for 10hr, filtered out the carbon ball without washing and dried directly, then took 1mol of potassium hexacyanoferrate and loaded it into the pores of the above-mentioned carbon ball adsorbed with cobalt nitrate by an equal volume impregnation method, 80 o The reaction was carried out at 400 °C for 24 hours. The carbon spheres were thoroughly washed with water until the effluent was completely colorless, and then dried to obtain a carbon sphere material loaded with potassium hexacyanoferrate. The loading of potassium hexacyanoferrate, the active adsorption component, was only 0.03%. This is because the cobalt ions in the carbon spheres are not fixed, but are soluble cobalt nitrate. When encountering the hexacyanoferrate solution, they quickly dissolve and react with potassium hexacyanoferrate on the carbon sphere surface, blocking the potassium hexacyanoferrate solution from entering the carbon sphere interior. Potassium hexacyanoferrate is only generated in a small area of ​​the carbon sphere shell. This part of potassium hexacyanoferrate is lost in large quantities during subsequent washing, which is why the wash water of this material is difficult to turn colorless during subsequent washing. Due to the low content of potassium hexacyanoferrate in the material, its adsorption performance for Cs ions is poor. The selective absorption capacity of the material for Cs ions was characterized by absorbing 1 mg / L of Cs ions in H ions, Na ions, and K ions at concentrations of 1 mol / L, 0.5 mol / L, and 0.1 mol / L, respectively. The adsorption time was 12 h, and the distribution coefficient of the adsorbent was calculated according to the formula (0.2 g of absorbent and 50 mL of absorption liquid):

[0143] Kd = ( C 0 - C 1 ) F / C 1

[0144] In the formula C 0 : Cs ion concentration in the solution before adsorption (=1000 μg / L); C 1 : ion concentration in the solution after adsorption (mg / L); F :The mass ratio of the absorption liquid volume to the adsorbent (50 / 0.2=250mL / g).

[0145] The Cs ion concentration in the liquid after absorption is shown in Table 11:

[0146] Table 11 Cs ion concentration in the liquid in Comparative Example 2

[0147] Interfering ions and concentrations Final Cs ion concentration (μg / L) <![CDATA[H + 1mol / L (HCl)]]> 202.8 983 <![CDATA[H + 0.5mol / L (HCl)]]> 315.7 542 <![CDATA[H + 0.1mol / L (HCl)]]> 376.2 414 <![CDATA[Na + 0.1 mol / L(NaCl)]]> 396.5 380 <![CDATA[Na + 0.5 mol / L(NaCl)]]> 454.3 300 <![CDATA[Na + 1mol / L(NaCl)]]> 496.8 253 <![CDATA[K + 0.1mol / L(KCl)]]> 512.7 238 <![CDATA[K + 0.5mol / L(KCl)]]> 812.1 57.8 <![CDATA[K + 1mol / L(KCl)]]> 886.4 32

[0148] From the adsorption test results, it can be seen that the adsorption activity of the material for Cs ions is poor due to the low content of active components.

Claims

1. A method for preparing a Cs ion selective adsorption material, characterized in that: The material carrier is a spherical carbon material obtained by carbonizing a spherical ion exchanger, and the active component is hexacyanoferrate particles loaded inside the spherical carbon material. First, non-Group IA metal ions are loaded on adsorption sites inside the spherical carbon material, and then a soluble hexacyanoferrate solution is immersed in the spherical carbon material. The non-Group IA metal ions and the soluble hexacyanoferrate undergo a co-precipitation reaction to generate hexacyanoferrate particles containing non-Group IA metal ions, which are then in-situ fixed inside the spherical carbon material to obtain the Cs ion selective adsorption material. The spherical carbon material is obtained by carbonizing an acidic or alkaline styrene ion exchange resin, or the spherical carbon material is obtained by carbonizing an acidic or alkaline phenolic resin ion exchange resin; The spherical carbon material is pre-oxidized, and its surface carboxyl content is 0.1 mmol / g to 5 mmol / g; The non-Group IA metal ion is Ca 2+ Mg 2+ 、Sr 2+ 、Ba 2+ 、Cu 2+ 、Zn 2+ 、Co 2+ 、Ni 2+ , Pb 2+ 、Fe 3+ Cr 3+ 、La 3 + 、Ag + 、Mn 2+ 、Al 3+ Any one or a mixture of any several of them in any proportion, the amount of which is 0.1 to 3 times the amount of the carboxyl substance in the spherical carbon material; The spherical carbon material has a hard and dense spherical shell.

2. The preparation method according to claim 1, characterized in that The pre-oxidant of the spherical carbon material is one of HNO3, H2O2, acidic potassium permanganate and acidic potassium dichromate, or a mixture of any of them in any proportion.

3. The preparation method according to claim 1, characterized in that The soluble hexacyanoferrate is any one of potassium hexacyanoferrate, sodium hexacyanoferrate, and ammonium hexacyanoferrate, or a mixture of any of them in any proportion, and its usage is 0.3 to 5 times the amount of the carboxyl substance in the spherical carbon material.

4. The preparation method according to claim 1, characterized in that The soluble hexacyanoferrate solution that reacts with the non-Group IA metal ions already present in the spherical carbon material is acidic, and its [H + ]=0.01~2mol / L.

5. The preparation method according to claim 1, characterized in that The reaction temperature of non-Group IA metal ions inside the spherical carbon material and soluble hexacyanoferrate is 20~100 ℃, and the reaction time is 0.5~48 hr.

6. A Cs ion selective adsorption material, characterized in that: Prepared by the preparation method according to any one of claims 1 to 5.

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