▎ 摘　　要

NOVELTY - Complex material comprises graphene oxide, on a substrate loaded with magnetic nanoparticles and nitrilotriacetic acid. USE - The complex material is useful for removing tetracycline in waste water (claimed). ADVANTAGE - The complex material has good absorption effect. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing complex material comprising (1) taking 6 g graphite powder, 5 g potassium persulfate, 5 g phosphorus pentoxide, adding to 24 ml of 98 % sulfuric acid in triangular cone into the bottled water bath with stirring, oxidizing at 80 degrees C for 4.5 hours, cooling to room temperature, adding 1 l diluted ultrapure water and allowing to stand overnight for 12 hours, filtering the mixture and washing with deionized water until residual acid to neutral at 60 degrees C in an oven drying to obtain pre-oxidation of graphite; (ii) adding pre-oxidation of graphite to 240 ml 98 % sulfuric acid solution (0 degrees C), adding 5g sodium nitrate, 30 g potassium permanganate with stirring reaction at 0 degrees C for 4 hours, then raising the reaction temperature to 35 degrees C for 2 hours, adding 500 ml ultrapure water to the reaction at 98 degrees C for 1 hour, then continuing to add 1 l ultrapure water at room temperature and 40 ml 30 % hydrogen peroxide, continuing the reaction for two hours, washing the mixture with 10 % hydrochloric acid, then washing with copious amounts of water until neutral and adding water at 50 degrees C, ultrasonically dispersing for 2 hours with an aqueous suspension of graphene oxide; (iii) taking 1 g graphene oxide, heating at 85 degrees C in water bath, stirring, taking 0.01 mol ferric chloride, 0.005 mol ferrous sulfate, dissolving in 100 ml water, using mixture then adding graphene oxide, stirring for 2 minutes, further adding aqueous ammonia, adjusting pH to 10, stirring for 45 minutes and magnetic separation washing; and (iv) adding 0.2 g 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 0.2 g N-hydroxysuccinimide room temperature to the aqueous solution containing 0.4 g nitrilotriacetic acid, stirring was continued for two hours, then adding (3) step magnetic graphene oxide dispersion liquid and 20 ml diethylenetriamine, stirring the mixed solution continuously at 80 degrees C in water bath for 6 hours, rinsing the product with deionized water to neutral.