Method for removing salt in papermaking wastewater by using modified double ion exchange resin

The invention discloses a method for removing salt in papermaking wastewater by using modified double ion exchange resin. The preparation method comprises the following steps: taking 201 * 7 oxyhydrogen anion exchange resin as a raw material, fully reacting with a mixed solution of ferric citrate, ethanol and water under an acidic condition, and loading iron oxyhydroxide on the surface of the resin by using a strong alkali solution to obtain the modified 201 * 7 oxyhydrogen anion exchange resin. Compared with the prior art, the modified resin has the advantages that the exchange capacity of sulfate radicals is increased, other ions are not introduced, the regeneration effect is excellent, and no iron ions are dissolved out. The modified resin is combined with 732 hydrogen type cation exchange resin to effectively remove cations and anions in the papermaking wastewater, the use amount and proportion of the cation and anions are controlled, the salt content and pH of effluent can be controlled, and the method f