A preparation method of a bismuth ion filter membrane, comprising the following steps:
- step (1), pre-treatment of a filter membrane substrate:
- placing the filter membrane substrate into a cleaning machine, adding a non-ionic chelating agent solution and water to the cleaning machine, soaking and stirring the filter membrane substrate, and then performing dehydration on the filter membrane substrate to obtain a filter membrane substrate A;
- step (2), embedding of bismuth ions:
- adding the filter membrane substrate A obtained in the step (1) and a chelated bismuth ion solution to a reactor, followed by adding a non-ionic chelating agent solution to the reactor to perform a reaction to thereby obtain a filter membrane substrate embedded with the bismuth ions;
- and
- step (3), post-treatment:
- dehydrating and drying the filter membrane substrate embedded with the bismuth ions obtained in the step (2) to obtain the bismuth ion filter membrane;
- and
- wherein a preparation method of the chelated bismuth ion solution in the step (2) comprises the following steps:
- S1, adding flake graphite to a hydrogen peroxide (H2O2)/sulfuric acid (H2SO4) solution to obtain a flake graphite mixed solution, stirring the flake graphite mixed solution at room temperature for 10 minutes (min), followed by filtering and washing the flake graphite to obtain washed flake graphite, and then calcining the washed flake graphite in a nitrogen atmosphere at 500° C. to 600° C. for 10 min to 20 min to obtain pre-treated flake graphite;
- and adding the pre-treated flake graphite to an ethanol aqueous solution with a volume ratio of 1:1, performing an ultrasonic treatment on the pre-treated flake graphite under a stirring condition for 8 hours (h) to 12 h, and performing vacuum drying on the pre-treated flake graphite after the ultrasonic treatment to obtain flaky graphite;
- S2, adding the flaky graphite obtained in the step S1 to an ethanol aqueous solution, then adding γ-glycidoxypropyltrimethoxysilane to the flaky graphite with the ethanol aqueous solution to obtain a mixture, performing a stirring reaction on the mixture to react to obtain a reaction product, and then performing filtering, washing, and drying on the reaction product to obtain pre-treated flaky graphite;
- and adding the pre-treated flaky graphite to dimethyl sulfoxide, followed by adding 2-guanidinobenzimidazole to obtain a pre-treated flaky graphite mixed solution, adjusting a pH of the pre-treated flaky graphite mixed solution to 10-12, and performing a constant-temperature reaction in a nitrogen atmosphere to obtain modified flaky graphite;
- and
- S3, adding 50 parts by weight of the modified flaky graphite in the step S2 to 920 parts by weight of deionized water, then adding 10 parts by weight of chitosan to obtain a modified flaky graphite mixed solution, adjusting a pH of the modified flaky graphite mixed solution to 2-3 to thereby obtain an adjusted flaky graphite mixed solution, stirring and reacting the adjusted flaky graphite mixed solution at 40° C. to 50° C. for 4 h to 6 h, followed by adding 20 parts by weight of bismuth ion solution to obtain a bismuth ion mixed solution, and reacting the bismuth ion mixed solution at 60° C. to 70° C. for 3 h to 4 h to obtain the chelated bismuth ion solution.