▎ 摘　　要

NOVELTY - A graphene oxide loaded magnetic nano-iron material comprises graphene oxide as framework to carry nano-iron particles. The mass ratio of graphene oxide and nano-iron particles is 3:45 to 3:55. The particle size of nano-iron particles is 20-100 nm. USE - Graphene oxide loaded magnetic nano-iron material for magnetic separation in underground medium for repairing groundwater pollution. ADVANTAGE - The graphene oxide loaded magnetic nano-iron material improves the oxidation resistance of the nano-iron particles, adsorption, stability, mobility and magnetic separation characteristics, and has high chromium heavy metal pollutants removal efficiency. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of graphene oxide loaded magnetic nano-iron material, which involves (1) dissolving 0.06-10 g of dried graphene oxide in 1000 ml deionized water, ultrasonically treating for 2-4 hours to obtain graphene oxide suspension, (2) dripping 0.0714 mol/l ferrous salt solution into the graphene oxide suspension, stirring for 30 minutes, (3) dripping 0.715 mol/l aqueous solution of borohydride under anaerobic conditions by high performance liquid phase reduction method, stirring at room temperature for 4 hours, reducing iron ions to iron oxide, loading on the surface of graphene oxide, (4) magnetically collecting the graphene oxide loaded nano-iron material, washing product with deionized water and absolute ethanol for 2-4 times under the protection of inert gas, and drying in vacuum oven at 60 degrees C for 18-24 hours.