▎ 摘　　要

NOVELTY - Preparation of 5-methylbenzotriazole-functionalized graphene oxide adsorbent involves dispersing 0.1-1 g graphene oxide intermediate in 10-100 mL dimethylformamide, ultrasonically processing for 15-30 minutes, adding 0.2-2 g 5-methylbenzotriazole and 0.83-8.3 g anhydrous potassium carbonate, refluxing in nitrogen atmosphere at 85 degrees C for 8-24 hours, filtering using 0.22 mu m organic microporous filter film, washing with dimethylformamide, dispersing resultant solid in 10-100 mL deionized water and acetone, ultrasonically processing for 10-30 minutes, filtering, washing, and drying. USE - Preparation of 5-methylbenzotriazole-functionalized graphene oxide adsorbent used for selective co-removal of lanthanum/actinide elements, and removal of radioactive elements including actinide e.g. thorium(IV) or uranium(VI), lanthanide e.g. lanthanum(III), neodymium(III), samarium(III), niobium(III) or cerium(III), divalent transitional metal e.g. zinc(II), cobalt(II), nickel(II) or manganese(II), alkaline earth metal e.g. strontium(II), and monovalent alkali metal e.g. cesium(I) from water (all claimed). ADVANTAGE - The method enables simple and environmentally-friendly preparation of 5-methylbenzotriazole-functionalized graphene oxide adsorbent having excellent stability, adsorption capacity, and selective co-adsorption property, electivity coefficient of 100%, and ligand graft rate of 6.4%, with high repeatability. The adsorbent enables easy and selective co-removal of lanthanum/actinide from low-middle-level waste liquid, and can be used repeatedly. DETAILED DESCRIPTION - Preparation of 5-methylbenzotriazole-functionalized graphene oxide adsorbent involves dispersing 0.1-1 g graphene oxide intermediate in 10-100 mL dimethylformamide, ultrasonically processing for 15-30 minutes, adding 0.2-2 g 5-methylbenzotriazole and 0.83-8.3 g anhydrous potassium carbonate, refluxing in nitrogen atmosphere at 85 degrees C for 8-24 hours, filtering using 0.22 mu m organic microporous filter film, washing with dimethylformamide 3-6 times, dispersing resultant solid in 10-100 mL deionized water and acetone, ultrasonically processing for 10-30 minutes, filtering using organic micro-filtration membrane, washing with deionized water and acetone 3-6 times, and drying in a vacuum drying box at 45 degrees C. The graphene oxide intermediate is prepared by dispersing 0.1-1 g graphene oxide powder as raw material in 40-400 mL deionized water, ultrasonically processing at room temperature for 10-30 minutes, adding 0.68-6.8 g anhydrous potassium carbonate and 10-100 mL dichloromethane, stirring at room temperature for 10-120 minutes, adding bromoacetyl bromide dissolved in 20-200 mL dichloromethane, stirring in ice bath for 1-3 hours, reacting, stirring at room temperature for 24-72 hours, distilling under reduced pressure to remove dichloromethane, centrifuging at 8000 rpm for 10-30 minutes, washing with deionized water for 3-6 times, centrifuging, ultrasonically dispersing in 20-200 mL acetone, filtering using 0.22 mu m organic microporous filter film, washing with 20-200 mL acetone, and drying at 45 degrees C. Also claimed is selective co-removal of lanthanum/actinide elements using the adsorbent. The selective co-removal of lanthanum/actinide elements involves adding 5 mg adsorbent and 20 mL 0.1-1 mmol metal ion solution having pH of 1-4.5 to 50 mL conical bottle, ultrasonically mixing for 5 minutes, centrifuging at 8000 rpm for 10 minutes, solid-liquid separating or filtering using water phase needle filter, and analyzing concentration of cation in resultant supernatant fluid or filtrate by inductively coupled plasma atomic emission spectroscopy analysis. An INDEPENDENT CLAIM is included for removal of radioactive elements from water.