▎ 摘　　要

NOVELTY - Method for preparing a magnesium oxide/graphene quantum dots/chitosanoligosaccharide/poly (vinyl alcohol) complex absorption membrane involves (a) preparing magnesium oxide/graphene quantum dots nanocomplex, (b) preparing magnesium oxide/graphene quantum dots/chitosanoligosaccharides nanocomplex, and (c) preparing a magnesium oxide/graphene quantum dots/chitosanoligosaccharide/poly (vinyl alcohol) complex absorption membrane by dissolving the lyophilized magnesium oxide/graphene quantum dots/chitosan oligosaccharide nanocomplex powder in water together with poly (vinyl alcohol), and spinning mixed solution to form the complex adsorption membrane. USE - The method is useful for preparing magnesium oxide/graphene quantum dots/chitosanoligosaccharide/poly (vinyl alcohol) complex absorption membrane, which is used in wastewater treatment (all claimed). ADVANTAGE - The method prepares magnesium oxide/graphene quantum dots/chitosanoligosaccharide/poly (vinyl alcohol) complex absorption membrane, which has large adsorption capacity, good mechanical strength, recoverability and excellent biological properties. DETAILED DESCRIPTION - Method for preparing a magnesium oxide/graphene quantum dots/chitosanoligosaccharide/poly (vinyl alcohol) complex absorption membrane involves (a) preparing magnesium oxide/graphene quantum dots nanocomplex by adding a magnesium chloride solution in a drop wise manner to a dispersion of graphene oxide quantum dots and uniformly stirring to obtain a mixed solution of magnesium chloride solution and dispersion of graphene oxide quantum dots, adding a surfactant, reacting while adjusting a pH to 8-10, at the end of the reaction, cooling, filtering, rinsing for several times, drying, and calcining to obtain magnesium oxide/graphene quantum dots nanocomplex, (b) preparing magnesium oxide/graphene quantum dots/chitosanoligosaccharides nanocomplex by dissolving chitosan oligosaccharide in an acetic acid solution, adding the magnesium oxide/graphene quantum dots nanocomplex, and a cross-linking agent, magnetically stirring at 18-23° C for 60-90 minutes while adjusting a pH to 9-12, and magnetically stirring continuously at 60-80° C for 0.8-1.5 hours, finally, washing resulting mixture for several times until neutral and freeze-drying to obtain magnesium oxide/graphene quantum dots/chitosan oligosaccharide nanocomplex powder, and (c) preparing a magnesium oxide/graphene quantum dots/chitosanoligosaccharide/poly (vinyl alcohol) complex absorption membrane by dissolving the lyophilized magnesium oxide/graphene quantum dots/chitosan oligosaccharide nanocomplex powder in water together with poly (vinyl alcohol), and spinning mixed solution to form the complex adsorption membrane. INDEPENDENT CLAIMS are included for the following: complex absorption membrane of magnesium oxide/graphene quantum dots/chitosan oligosaccharide/poly (vinyl alcohol) prepared by the method; and use of the complex adsorption membrane in wastewater treatment.