In the natural state,  exists in the form of organic  and inorganic . Most of them come from domestic sewage, wastewater from factories and animal husbandry, and they are also present in a large number of industries such as chemical industry, biochemical pharmacy, and metal surface.  is a key nutrient that causes eutrophication of water bodies. It not only causes the algae in the water to grow wild, but also causes the oxygen content of the water body to drop sharply, affecting the survival of fish and other aquatic organis.
 removal by ion exchange resin adsorption has the advantages of low environmental requirements, simple process, and low operating cost. The research on resin adsorption  removal has attracted more and more attention.