▎ 摘　　要

NOVELTY - Preparing composite material comprises (i) uniformly stirring to mix ferric chloride and ferrous chloride in graphene oxide dispersion, adjusting pH to 9.5 plus minus 0.5, and reacting at room temperature to obtain magnetic graphene oxide, and (ii) uniformly stirring to ultrasonically dissolve sodium alginate and sodium carboxymethyl cellulose in magnetic graphene oxide dispersion, dripping mixed solution to a 5 plus minus 2 wt.% calcium chloride solution, soaking at room temperature, washing using water, and drying to obtain magnetic graphene oxide/sodium alginate/carboxymethyl cellulose sodium composite material, where the mass ratio of magnetic graphene oxide, sodium alginate and sodium carboxymethyl cellulose is 1-5:10:5-10. USE - The material is useful for adsorbing heavy metal ions, preferably copper ions (all claimed). ADVANTAGE - The material has active functional groups, improved adsorption property, and achieves maximum adsorption capacity of 92.6 mg/g. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) the composite material; and (2) use method of the composite material comprising adjusting pH of wastewater containing heavy metal ions to 3-10, and adding composite material for adsorption.