Preparation method of double ionic straw based hydrogel applied for sewage treatment

The invention provides a preparation method of a double ionic straw based hydrogel with a function of capturing a dyeing material in sewage. Carboxymethylation is performed on straw through a one-step method and the double ionic straw based hydrogel is synthesized through graft copolymerization. As carboxylate anions and monomer ions of carboxymethylcellulose exist in the prepared three dimensional net structured hydrogel, under the cooperation of static electricity and hydrogen bond, the hydrogel has a relatively strong adsorbing action for anion dye, cation dye and heavy metals in a water medium.