Resin for removing phosphorus from water body, and preparation method therefor and application thereof

A method for preparing a resin for removing phosphorus from waste water solution, wherein the method comprises the following steps of:

• step (1):
• preparing an oil phase using a monofunctional monomer, a cross-linking agent, a pore-forming agent and an initiator, preparing an aqueous phase using a dispersant and water, preparing a resin via suspension polymerization reaction, and removing the pore-forming agent from the resin after polymerization reaction is completed, obtaining a resin-based sphere, wherein the suspension polymerization reaction in the step (1) is carried out at a temperature of 40-100° C. using a gradient heating method which comprises heating to 40-60° C. at a first stage, 60-80° C. at a second stage and 80-100° C. at a third stage;
• step (2):
• carrying out a chlorination reaction and an amination reaction of the resin-based sphere, and carrying out a hydrolysis reaction by adding an alkali to the resin after the amination reaction, obtaining an amine sphere;
• step (3):
• reacting the amine sphere with an organic weak acid, obtaining a weak acid cation resin;
• and
• step (4):
• loading a lanthanum compound onto the surface of the weak acid cation resin, obtaining a resin for removing phosphorus;
• wherein the resin has a particle size of 0.5-0.8 mm;
• a porous structure with a specific surface area of 8-25 m2/g and a pore size distribution of 3-15 nm;
• a wet apparent density of 0.68-0.74 g/cm3;
• a wet true density of 1.12-1.18 g/cm3;
• a water content of 43-57% by weight;
• and is loaded with a functional group having a lanthanum-oxygen bond to enable selectively adsorbing of phosphate ions from waste water solution by the resin.