▎ 摘　　要

NOVELTY - Composite hydrogel comprises polyethylene alcohol, chitosan, modified graphene oxide, and sodium alginate. The modified graphite oxide is ferroferric oxide. USE - The composite hydrogel is useful for adsorption of heavy metal ions in industrial wastewater (all claimed). ADVANTAGE - The composite hydrogel can be simply and rapidly prepared with high adsorption capacity, good stability and strong operability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparing the composite hydrogel, comprising adding the polyethylene alcohol, sodium alginate, and deionized water in a bottle and then mixing, stirring the mixture for 1-4 hours and heating to obtain mixed liquid, adding the mixed liquid in a water bath and then heating at temperature of 60-100 degrees C, adding chitosan and then stirring for 2-10 hours and cooling to room temperature, adding 1-5 pts. wt. modified graphene oxide and then stirring for 0.2-2 hours and dispersing, dropping the modified graphene oxide solution into calcium chloride-boric acid saturated solution and then reacting to obtain spherical hydrogel having a grain diameter size of 0.5-10 mm, soaking the spherical hydrogel with saturated solution for 12-36 hours and then flushing with 2-6 times of deionized water.