Application of cationic polyester-based filtering material in filtering gel particles in nuclear power water

Abstract

The invention belongs to the technical field of filter materials, and discloses an application of a cationic polyester-based filter material in filtering gel particles in nuclear power water.The cationic polyester-based filter material is a cationic polyester fabric with the surface grafted with PEI; the molecular weight of the PEI, the Zener potential of the cationic polyester-based filtering material when the pH value is equal to 7, the average physical semi-pore size of the cationic polyester-based filtering material, the porosity of the cationic polyester-based filtering material, the average physical radius of gel particles in the nuclear power water to be removed, and the Zener potential of the gel particles in the nuclear power water to be removed are calculated according to the molecular weight of the PEI, the average physical semi-pore size of the cationic polyester-based filtering material and the porosity of the cationic polyester-based filtering material. After the apparent velocity of the nuclear power water meets the relational expression provided by the invention, the retention rate of the gel particles in the nuclear power water can be effectively improved. The cationic polyester-based filtering material can effectively filter gel particles in nuclear power water, has high efficiency, durability and economical efficiency, and has a good application prospect in filtering the gel particles in the nuclear power water.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of filter materials and relates to application of a cationic polyester-based filter material to filter out gel particles in nuclear power water. BACKGROUND

[0002] In the field of nuclear power water treatment, gel particles are formed by colloidal substances, corrosion products or organic polymers, with sizes ranging from nanometers to microns, and have viscoelasticity, deformability and adsorbability. These particles are derived from metal corrosion of the reactor coolant system (such as oxides of iron, nickel and chromium), decomposition of chemical additives or microbial metabolites. Due to the special physicochemical properties of gel particles, in the nuclear power water system, they can adsorb radioactive nuclides (such as Co, 60 Co、 137 Cs), forming radioactive colloids, greatly increasing the complexity of water treatment. The deposition behavior of gel particles not only leads to a decrease in heat transfer efficiency and local corrosion, but also may diffuse with the help of carrying radioactive substances, increasing the risk of radiation. In addition, gel particles can also block the pores of ion exchange resins, reducing the treatment efficiency and increasing the operation and maintenance cost.

[0003] However, traditional filter materials (such as activated carbon and ceramic membranes) have low adsorption capacity, are prone to blockage and have poor radiation resistance, and therefore cannot be used to filter out gel particles in nuclear power water.

[0004] Cationic polyester is a polyester fiber with cationic groups introduced through chemical modification. The core modification process is to add sulfonic acid groups and other additives to the molecular chain, so that the fiber has unique dyeing performance and functional characteristics. Compared with ordinary polyester, cationic polyester performs excellently in terms of dyeing, moisture absorption, antistatic property and antibacterial property, and the fiber surface microporous structure enhances the adsorption capacity of liquid and particles, providing significant advantages for the field of filter materials.

[0005] In the prior art, the application of cationic polyester-based filter materials is mainly concentrated in the following fields:

[0006] Industrial filtration: used in chemical liquid filtration, metallurgical slag separation and other scenes due to its chemical corrosion resistance and wear resistance;

[0007] Medical and food: used in pharmaceutical filtration and food clarification in fields with high cleanliness requirements due to its antibacterial property and low particle shedding characteristics;

[0008] Environmental protection field: in sewage treatment, its high moisture absorption and anti-fouling properties improve the solid-liquid separation efficiency.

[0009] Although cationic polyester performs well in conventional filtration scenarios, it is difficult to meet the requirements of nuclear power water treatment, such as filtration accuracy, interception rate, etc. For example, the patent with the authorization announcement number CN206867852U discloses a polyester needle punching filter felt with high efficiency filtration and high strength, which is made of 6D polyester fiber as base cloth, and has annular reinforcing cloth on both sides of the base cloth, and 2.5D polyester fiber as a filter layer, and the outer side of the filter layer is coated with a polytetrafluoroethylene film with micropores, so that the overall strength is improved and the gradient filtration characteristics are also possessed. However, when it is used for nuclear power water treatment, due to the insufficient accuracy of the filter layer, it is difficult to effectively filter the submicron or even nanometer radioactive particles, colloids and the like in the nuclear power water, resulting in low interception rate.

[0010] Therefore, it is of great significance to study the application of a cationic polyester-based filter material to solve the above problems. SUMMARY

[0011] The purpose of the present application is to solve the problems existing in the prior art, and to provide an application of a cationic polyester-based filter material in filtering gel particles in nuclear power water.

[0012] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0013] The application of a cationic polyester-based filter material is used to filter gel particles in nuclear power water.

[0014] The cationic polyester-based filter material is a cationic polyester fabric with PEI grafted on the surface, and the PEI is a hyperbranched polyethyleneimine;

[0015] The molecular weight M of the PEI, the zeta potential Ub1 of the cationic polyester-based filter material at pH=7, the average physical half-pore diameter Rp of the cationic polyester-based filter material, the porosity p of the cationic polyester-based filter material, the average physical radius rp of the gel particles in the nuclear power water to be removed, the zeta potential Ub2 of the gel particles in the nuclear power water to be removed, and the apparent flow rate Vs of the nuclear power water satisfy the following relationship:

[0016] (rp x (1-0.2(Vs / p / Ka))) >= 0.729(Rp-(kb2 x kb1 x ((Ub1-Ub2)^0.19) x (Km^1 / 3) x beta^0.2));

[0017] In the formula:

[0018] The unit of rp is μm;

[0019] The unit of Vs is mm / s;

[0020] The value of Ka is 2, and the unit is mm / s;

[0021] Rp is in units of μm;

[0022] kb2 is related to Vs / ρ, when Vs / ρ>5mm / s, kb2=0, when Vs / ρ≤5mm / s, kb2=1;

[0023] kb1 is in units of 0.0165 μm×(mv^-0.19)×(Da^-1 / 3);

[0024] Ub1 is in units of mV;

[0025] Ub2 is in units of mV;

[0026] Km is related to the molecular weight M of PEI, when M≤70000Da, Km=M, when M>70000Da, Km=70000Da;

[0027] β is related to Vs, ρ, Kv, if Vs / ρ≥Kv, β=0, otherwise, β=1-Vs / ρ / Kv; Kv is in units of 4 mm / s.

[0028] The derivation process of the above relationship is as follows:

[0029] The filtration efficiency Fe depends on the average equivalent half-pore diameter Re(μm) of the textile (i.e. the cationic polyester-based filter material) and the average equivalent radius re(μm) of the gel particles; when re>Re, Fe=100%; when re≤Re, Fe=(re / Re)^(1 / 3)×100%;

[0030] When Fe≥90%, the filtration effect is relatively ideal, according to the above analysis, to make Fe≥90%, it is required to control (re / Re)≥0.729, i.e. to control re≥0.729Re.

[0031] The average equivalent half-pore diameter Re(μm) of the textile depends on the average physical half-pore diameter Rp(μm) of the textile, the actual flow rate Va(mm / s) of the nuclear power water, and the boundary layer thickness Tb1(μm) of the textile; tests show that Re=Rp-(Tb1×β^0.2), wherein β is related to Va, Kv, if Va≥Kv, β=0, otherwise, β=1-Va / Kv;

[0032] The actual flow rate Va(mm / s) of the nuclear power water depends on the superficial flow rate Vs(mm / s) of the nuclear power water and the porosity ρ(%) of the textile, Va=Vs / ρ;

[0033] The thickness Tb1 (μm) of the textile surface layer depends on the zeta potential Ub1 (mV) of the textile at pH = 7, the zeta potential Ub2 (mV) of the gel particles, the molecular weight M (Da) of the PEI, and experiments show that Tb1 = kb2 x kb1 x ((Ub1-Ub2)^0.19) x (Km^1 / 3), when M≤70000 Da, Km=M, when M>70000 Da, Km=70000 Da, when Va>5 mm / s, kb2=0, when Va≤5 mm / s, kb2=1, the value of kb1 is positively correlated with the amount of positive charges remaining on the surface of the textile, the more positive charges remaining on the surface of the textile, the greater the value of kb1, and vice versa, the less positive charges remaining on the surface of the textile, the smaller the value of kb1; compared with the pure PET substrate, the sulfonic acid group in the cationic polyester substrate of the application carries more negative charges, plus the original carboxyl group, which can offset more positive charges of PEI, and the value of kb1 is relatively smaller, which is 0.0165, unit: μm x (mv^-0.19) x (Da^-1 / 3);

[0034] Therefore, Re=Rp-(Tb1 x (1-Va / Kv)^0.2)=Rp-(kb2 x kb1 x ((Ub1-Ub2)^0.19) x (Km^1 / 3) x β^0.2).

[0035] The average equivalent radius re (μm) of the gel particles depends on the physical average radius rp (μm) of the gel particles and the deformation factor Df (dimensionless) of the gel particles, and experiments show that re=rp x Df, Df=1-0.2(Va / Ka), wherein the value of Ka is 2, unit: mm / s, i.e. re=rp x (1-0.2(Va / Ka))=rp x (1-0.2(Vs / ρ / Ka)).

[0036] Control re≥0.729Re, i.e. control (rp x (1-0.2(Vs / ρ / Ka)))≥0.729(Rp-(kb2 x kb1 x ((Ub1-Ub2)^0.19) x (Km^1 / 3) x β^0.2)).

[0037] Therefore, to achieve the ideal filtering effect, it is necessary to control (rp x (1-0.2(Vs / ρ / Ka)))≥0.729(Rp-(kb2 x kb1 x ((Ub1-Ub2)^0.19) x (Km^1 / 3) x β^0.2)).

[0038] When the particle size distribution of the gel particles in the nuclear power water is wide, the gel particles in the nuclear power water can be removed in steps, for example, in three steps. In the first step, the gel particles in the nuclear power water with a relatively large particle size are removed as the target gel particles in the nuclear power water, and a cationic polyester-based filter material with a suitable PEI molecular weight M, zeta potential Ub1, average physical half-pore size Rp, and porosity p is selected for filtration. In the second step, the gel particles in the nuclear power water with a moderate particle size are removed as the target gel particles in the nuclear power water, and a cationic polyester-based filter material with a suitable PEI molecular weight M, zeta potential Ub1, average physical half-pore size Rp, and porosity p is selected for filtration. In the third step, the gel particles in the nuclear power water with a relatively small particle size are removed as the target gel particles in the nuclear power water, and a cationic polyester-based filter material with a suitable PEI molecular weight M, zeta potential Ub1, average physical half-pore size Rp, and porosity p is selected for filtration.

[0039] As a preferred technical solution:

[0040] The application of the cationic polyester-based filter material as described above, the PEI molecular weight M is 3kDa-100kDa, which needs to be converted to 3000Da-100000Da for calculation when participating in the calculation.

[0041] The application of the cationic polyester-based filter material as described above, the zeta potential Ub1 of the cationic polyester-based filter material at pH=7 is 5-50mV; the average physical half-pore size Rp of the cationic polyester-based filter material is 5-15μm, and the porosity p is 40-90%, preferably 40-75%.

[0042] The application of the cationic polyester-based filter material as described above, the average physical radius rp of the target removed gel particles in the nuclear power water is 3-12μm, the zeta potential Ub2 of the target removed gel particles in the nuclear power water is not more than-5mV, and the apparent flow rate Vs of the nuclear power water is 0.0833-1mm / s.

[0043] The application of the cationic polyester-based filter material as described above, the retention rate (i.e. the actual measured filtration efficiency) of the cationic polyester-based filter material for the target removed gel particles in the nuclear power water is 90.73-99.98%.

[0044] The application of the cationic polyester-based filter material as described above, the grammage of the cationic polyester-based filter material is 30-100g / m 2 .

[0045] The application of the cationic polyester-based filter material as described above, the cationic polyester fabric is a spunlace non-woven fabric made of cationic dyeable polyester fibers by using a spunlace process.

[0046] The application of the cationic polyester-based filter material as described above, the cationic dyeable polyester fiber has a fineness of 0.8-1.2 dtex.

[0047] The application of the cationic polyester-based filter material as described above, the specific process of grafting PEI on the surface of the cationic polyester fabric is as follows: the cationic polyester fabric is soaked in the PEI solution at 40-95℃ for 15-120 min, and then sequentially subjected to water washing and drying.

[0048] The application of the cationic polyester-based filter material as described above, the concentration of the PEI solution is 0.5-3.0 wt%.

[0049] Advantages:

[0050] (1) The cationic polyester-based filter material of the application has a zeta potential improved by grafting PEI on the surface, and cooperates with the design of the average pore size and porosity, so as to achieve the effect of effectively filtering out the gel particles in the nuclear power water, and the retention rate of the gel particles in the nuclear power water removed by the target can be more than 90%.

[0051] (2) The cationic polyester-based filter material of the application has high efficiency, durability and economy, and has a good application prospect in filtering out the gel particles in the nuclear power water. DETAILED DESCRIPTION

[0052] The application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope defined by the claims attached hereto.

[0053] The following are the test methods of the performance in each embodiment:

[0054] The molecular weight M of PEI is determined by gel permeation chromatography (GPC) method. The PEI sample is prepared into a solution with a concentration of 1-5 mg / mL, tetrahydrofuran is used as the mobile phase, the flow rate is set to 1.0 mL / min, PLgel MIXED-C gel chromatographic column is selected, differential refractive detector (RI) and light scattering detector (LS) are used for detection, and standard curve is drawn by using standard polymers (polystyrene) with known molecular weight as standard sample. The molecular weight value of PEI is directly read and recorded from the standard curve or the instrument software.

[0055] The average physical radius rp of the gel particles in the nuclear power water removed by the target is determined according to the ISO 22412:2017 standard.

[0056] Zeta potential Ub2 of the gel particles in the target removed nuclear power water: The zeta potential Ub2 of the gel particles in the nuclear power water was determined by electrophoretic light scattering method. 5-10 mL of the nuclear power water sample was placed in the sample cell of the zeta potential analyzer. The instrument applied an electric field to the two ends of the sample to make the charged gel particles move electrophoretically. The electrophoretic mobility of the particles was measured by laser Doppler effect. The zeta potential Ub2 of the gel particles was calculated according to Henry equation by combining the dielectric constant and viscosity of the sample.

[0057] Zeta potential Ub1 of the textile at pH = 7: The zeta potential Ub1 of the material surface was determined by flow potential method. The textile was cut into a 1*5 cm strip and fixed in the sample clamp of the flow potential instrument. 0.01 mol / L KCl aqueous solution (pH = 7) was used as the electrolyte, and the flow rate was controlled at 1 mL / min. The zeta potential Ub1 of the textile surface was calculated according to Henry equation by measuring the flow potential generated when the electrolyte flowed through the surface of the textile, combining the dielectric constant and viscosity of the solution.

[0058] Average physical half-pore size Rp of the textile: The average physical half-pore size Rp of the textile was determined according to the standard GB / T 32361-2015 “Separation membrane pore size test method bubble point and average flow rate method”.

[0059] Porosity p of the textile: The porosity p of the textile was determined according to method A in the standard GB / T 42697-2023 “Nonwoven porosity test method”.

[0060] Retention rate of the textile for the gel particles in the target removed nuclear power water: The concentration Co of the gel particles in the target removed nuclear power water was determined by laser particle size analyzer. Then the target removed nuclear power water was filtered through the textile. The filtered liquid was collected and the concentration C1 of the gel particles was determined. The retention rate of the textile for the gel particles in the target removed nuclear power water was calculated according to the formula retention rate = (C0-C1) / C0*100%.

[0061] Example 1

[0062] A cationic polyester-based filter material is a cationic polyester fabric grafted with PEI, PEI is hyperbranched polyethyleneimine, and the molecular weight M of PEI is 3 kDa.

[0063] The process flow of grafting PEI on the surface of the cationic polyester fabric is as follows:

[0064] (1) The cationic dyeable polyester fiber with a fineness of 1.2 dtex is made into a spunlace nonwoven fabric by a spunlace process, which is a cationic polyester fabric.

[0065] (2) The cationic polyester fabric was soaked in a PEI solution with a concentration of 0.5wt% at 40°C for 15 minutes, and then washed and dried in sequence to achieve PEI grafting on the surface of the cationic polyester fabric and obtain cationic polyester-based filter material.

[0066] The final cationic polyester-based filter material has a Zeta potential Ub1 of 5 mV at pH 7; the average physical semi-pore size Rp of the cationic polyester-based filter material is 6 μm, the porosity ρ is 40%, and the basis weight is 100 g / m³. 2 .

[0067] The application of the above-mentioned cationic polyester-based filter material is as follows: the above-mentioned cationic polyester-based filter material is used to filter out gel particles in nuclear power plant water; wherein, the average physical radius rp of the gel particles in the target nuclear power plant water to be removed is 8 μm, the Zeta potential Ub2 of the gel particles in the target nuclear power plant water to be removed is -10 mV, and the apparent flow velocity Vs of the nuclear power plant water is 0.09 mm / s.

[0068] Tests showed that the cationic polyester-based filter material achieved a 99.98% rejection rate for gel particles in the target nuclear power plant water.

[0069] Example 2

[0070] A cationic polyester-based filter material is a cationic polyester fabric with PEI grafted onto its surface. PEI is hyperbranched polyethyleneimine, and the molecular weight M of PEI is 40 kDa.

[0071] The specific process flow for grafting PEI onto the surface of cationic polyester fabrics is as follows:

[0072] (1) A spunlace nonwoven fabric is made from cationic dyeable polyester fiber with a fineness of 0.8 dtex using a spunlace process, which is a cationic polyester fabric.

[0073] (2) The cationic polyester fabric was soaked in a 1wt% PEI solution at 50°C for 30 minutes, and then washed and dried in sequence to achieve PEI grafting on the surface of the cationic polyester fabric and obtain cationic polyester-based filter material.

[0074] The final cationic polyester-based filter material had a Zeta potential (Ub1) of 20 mV at pH 7; the average physical semi-pore size (Rp) of the cationic polyester-based filter material was 5 μm, the porosity (ρ) was 90%, and the basis weight was 30 g / m³. 2 .

[0075] The application of the cationic polyester-based filter material is specifically: the cationic polyester-based filter material is used to filter out gel particles in nuclear power water; wherein, the average physical radius rp of the gel particles in the nuclear power water to be removed is 3 μm, the zeta potential Ub2 of the gel particles in the nuclear power water to be removed is -15 mV, and the apparent flow rate Vs of the nuclear power water is 0.0833 mm / s.

[0076] Through testing, the cationic polyester-based filter material has a retention rate of 90.37% for the gel particles in the nuclear power water to be removed.

[0077] Example 3

[0078] A cationic polyester-based filter material is a cationic polyester fabric grafted with PEI, the PEI is hyperbranched polyethyleneimine, and the molecular weight M of the PEI is 60 kDa.

[0079] The process flow of grafting PEI on the surface of the cationic polyester fabric is specifically as follows:

[0080] (1) A cationic dyeable polyester fiber with a fineness of 0.95 dtex is used to prepare a spunlace non-woven fabric by a spunlace process, that is, a cationic polyester fabric;

[0081] (2) The cationic polyester fabric is soaked in a PEI solution with a concentration of 2 wt% at 60 ℃ for 60 min, then washed with water and dried, so as to graft PEI on the surface of the cationic polyester fabric and obtain a cationic polyester-based filter material.

[0082] The zeta potential Ub1 of the finally obtained cationic polyester-based filter material at pH = 7 is 30 mV; the average physical pore radius Rp of the cationic polyester-based filter material is 15 μm, the porosity ρ is 60%, and the grammage is 55 g / m 2 .

[0083] The application of the cationic polyester-based filter material is specifically: the cationic polyester-based filter material is used to filter out gel particles in nuclear power water; wherein, the average physical radius rp of the gel particles in the nuclear power water to be removed is 13 μm, the zeta potential Ub2 of the gel particles in the nuclear power water to be removed is -14 mV, and the apparent flow rate Vs of the nuclear power water is 1 mm / s.

[0084] Through testing, the cationic polyester-based filter material has a retention rate of 91.53% for the gel particles in the nuclear power water to be removed.

[0085] Example 4

[0086] A cationic polyester-based filter material is a cationic polyester fabric grafted with PEI, wherein PEI is a hyperbranched polyethyleneimine, and the molecular weight M of PEI is 70 kDa.

[0087] The process flow of grafting PEI on the surface of the cationic polyester fabric is as follows:

[0088] (1) A cationic dyeable polyester fiber with a fineness of 1.1 dtex is used to prepare a spunlace non-woven fabric by a spunlace process, which is a cationic polyester fabric;

[0089] (2) The cationic polyester fabric is soaked in a PEI solution with a concentration of 2.5 wt% at 95℃ for 100 min, and then washed and dried in sequence to graft PEI on the surface of the cationic polyester fabric, thereby obtaining the cationic polyester-based filter material.

[0090] The final cationic polyester-based filter material has a zeta potential Ub1 of 49 mV at pH = 7, an average physical half-pore diameter Rp of 13 μm, a porosity ρ of 80%, and a grammage of 45 g / m 2 .

[0091] The application of the above-mentioned cationic polyester-based filter material is as follows: the cationic polyester-based filter material is used to filter out gel particles in nuclear power water; wherein the average physical radius rp of the gel particles to be removed in the nuclear power water is 11 μm, the zeta potential Ub2 of the gel particles to be removed in the nuclear power water is -9 mV, and the apparent flow rate Vs of the nuclear power water is 0.88 mm / s.

[0092] Through testing, the retention rate of the cationic polyester-based filter material for the gel particles to be removed in the nuclear power water is 93.75%.

[0093] Example 5

[0094] A cationic polyester-based filter material is a cationic polyester fabric grafted with PEI, wherein PEI is a hyperbranched polyethyleneimine, and the molecular weight M of PEI is 100 kDa.

[0095] The process flow of grafting PEI on the surface of the cationic polyester fabric is as follows:

[0096] (1) A cationic dyeable polyester fiber with a fineness of 0.8 dtex is used to prepare a spunlace non-woven fabric by a spunlace process, which is a cationic polyester fabric;

[0097] (2) The cationic polyester fabric is soaked in a PEI solution with a concentration of 3 wt% at 95℃ for 120 min, and then washed and dried in sequence to graft PEI on the surface of the cationic polyester fabric, thereby obtaining the cationic polyester-based filter material.

[0098] The final cationic polyester-based filter material has a zeta potential Ub1 of 50 mV at pH = 7; the average physical half-pore diameter Rp of the cationic polyester-based filter material is 8 μm, the porosity ρ is 90%, and the grammage is 30 g / m 2 .

[0099] The application of the cationic polyester-based filter material is specifically: the cationic polyester-based filter material is used to filter out gel particles in nuclear power water; wherein the average physical radius rp of the gel particles in the nuclear power water to be removed is 7 μm, the zeta potential Ub2 of the gel particles in the nuclear power water to be removed is -8 mV, and the apparent flow rate Vs of the nuclear power water is 0.85 mm / s.

[0100] Through testing, the retention rate of the cationic polyester-based filter material for the gel particles in the nuclear power water to be removed is 97.83%.

Claims

1. Use of a cationic polyester-based filter material, characterized in that: Filtering gel particles in nuclear power water The cationic polyester-based filter material is a cationic polyester fabric with PEI grafted on the surface, and the PEI is a hyperbranched polyethyleneimine. The molecular weight M of the PEI, the zeta potential Ub1 of the cationic polyester-based filter material at pH=7, the average physical half-pore diameter Rp of the cationic polyester-based filter material, the porosity p of the cationic polyester-based filter material, the average physical radius rp of the gel particles in the nuclear power water to be removed, the zeta potential Ub2 of the gel particles in the nuclear power water to be removed, and the superficial velocity Vs of the nuclear power water satisfy the following relationship: (rp*(1-0.2(Vs / p / Ka)))>=0.729(Rp-(kb2*kb1*((Ub1-Ub2)^0.19)*(Km^1 / 3)*beta^0.2)); In the formula: The unit of rp is pm; The unit of Vs is mm / s; The numerical value of Ka is 2, and the unit is mm / s; The unit of Rp is pm; kb2 is related to Vs / p, when Vs / p>5 mm / s, kb2=0, and when Vs / p<=5 mm / s, kb2=1; The numerical value of kb1 is 0.0165, and the unit is pm*(mv^-0.19)*(Da^-1 / 3); The unit of Ub1 is mV; The unit of Ub2 is mV; Km is related to the molecular weight M of the PEI, when M<=70000 Da, Km=M, when M>70000 Da, Km=70000 Da; Beta is related to Vs, p, and Kv, if Vs / p>=Kv, beta=0, otherwise, beta=1-Vs / p / Kv; the numerical value of Kv is 4, and the unit is mm / s.

2. Use of a cationic polyester-based filter material according to claim 1, characterized in that, The molecular weight M of the PEI is 3kDa-100kDa.

3. Use of a cationic polyester-based filter material according to claim 2, characterized in that, The zeta potential Ub1 of the cationic polyester-based filter material at pH=7 is 5-50 mV; the average physical half-pore diameter Rp of the cationic polyester-based filter material is 5-15 pm, and the porosity p is 40-90%.

4. The use of a cationic polyester-based filter material according to claim 3, characterized in that, The average physical radius rp of the gel particles in the nuclear power water to be removed is 3-12 pm, the zeta potential Ub2 of the gel particles in the nuclear power water to be removed is not more than -5 mV, and the superficial velocity Vs of the nuclear power water is 0.0833-1 mm / s.

5. Use of a cationic polyester-based filter material according to claim 4, characterized in that, The retention rate of the cationic polyester-based filter material for the gel particles in the nuclear power water to be removed is 90.37-99.98%.

6. Use of a cationic polyester-based filter material according to claim 1, characterized in that, The cationic polyester-based filter material has a grammage of 30-100 g / m 2 .

7. Use of a cationic polyester-based filter material according to claim 1, characterized in that, The cationic polyester fabric is a spunlace non-woven fabric made of cationic dyeable polyester fibers by a spunlace process.

8. Use of a cationic polyester-based filter material according to claim 7, characterized in that, The fineness of the cationic dyeable polyester fibers is 0.8-1.2 dtex.

9. Use of a cationic polyester-based filter material according to claim 1, characterized in that, The specific process of grafting PEI on the surface of the cationic polyester fabric is as follows: the cationic polyester fabric is soaked in a PEI solution at 40-95°C for 15-120 min, and then washed with water and dried in sequence.

10. Use of a cationic polyester-based filter material according to claim 9, characterized in that, The concentration of the PEI solution is 0.5-3.0 wt%.