▎ 摘　　要

NOVELTY - Graphite powder and concentrated sulfuric acid are stirred, and potassium permanganate and hydrogen peroxide solution are added to mixture, cooled, dried and oxidized. Triethylenetetramine is added to mixture, stirred, filtered and dried, to obtain triethylenetetramine-graphene oxide. Triethylenetetramine-graphene oxide is added to mixture and cobalt nitrate hexahydrate, iron nitrate nonahydrate, polyethylene glycol and sodium acetate are added to mixture, stirred, reacted, filtered, washed and dried, to obtain cobalt-iron oxide-triethylenetetramine-graphene oxide adsorbent. USE - Preparation of cobalt-iron oxide-triethylenetetramine-graphene oxide adsorbent for absorbing chromium (VI) in wastewater. ADVANTAGE - The method enables preparation of cobalt-iron oxide-triethylenetetramine-graphene oxide adsorbent with high stability by economical method within short period of time. DETAILED DESCRIPTION - Graphite powder and concentrated sulfuric acid are mechanically stirred at 0-4 degrees C for 30-40 minutes under ice-cooling, and potassium permanganate is added to mixture and mixed for 1-2 hours, maintained at 0-4 degrees C, heated at 35-40 degrees C, mixed with mechanical stirrer for 60-90 minutes, and distilled water is dripped to mixture. The mixture is heated at 95-98 degrees C for 5-10 minutes, and distilled water is added to mixture. 30 %mass Hydrogen peroxide solution is added to mixture and processed to form golden yellow mixture. The mixture is cooled to room temperature, processed with 5% hydrochloric acid and washed with distilled water, to obtain dispersion of graphite oxide. Dispersion of graphite oxide is vacuum dried at 40-60 degrees C for 20-24 hours, to obtain graphite oxide powder. The mass ratio of graphite powder and concentrated sulfuric acid is 1 g:10-25 mL. The mass ratio of graphite powder and potassium permanganate is 1:2-5. The volume ratio of graphite and distilled water is 1 g:100-150 mL. The volume ratio of graphite and 30 %mass solution of hydrogen peroxide is 1 g:10-20 mL. The graphite powder is oxidized, added to distilled water and ultrasonically processed for 20-40 minutes. Aqueous ammonia is added to mixture, and pH is adjusted to 11-13. The mixture is placed in oil bath at 95-98 degrees C, and triethylenetetramine is added, stirred for 10-12 hours, vacuum filtered, washed with distilled water and ethanol and vacuum dried at 40-60 degrees C for 12-24 hours, to obtain triethylenetetramine-graphene oxide. The volume ratio of graphite oxide powder and distilled water is 1 mg:1-10 mL. The mass ratio of graphite powder and aqueous ammonia is 1-5 mg:1 mL. The mass ratio of graphite oxide powder and triethylenetetramine is 1 g:2-20 mL. Triethylenetetramine-graphene oxide is added to mixture, ultrasonically processed for 20-40 minutes, and cobalt nitrate hexahydrate, iron nitrate nonahydrate, polyethylene glycol 4000 and sodium acetate are added to mixture, stirred for 20-24 hours, ultrasonically processed for 20-30 minutes, added to reactor, reacted at 180-220 degrees C for 12-24 hours, vacuum filtered, washed with absolute ethanol and vacuum dried at 40-60 degrees C for 12-24 hours, to obtain cobalt-iron oxide-triethylenetetramine-graphene oxide adsorbent. The volume ratio of triethylenetetramine-graphene oxide and ethylene glycol is 1 g:1000-3000 mL. The mass ratio of triethylenetetramine-graphene oxide and cobalt nitrate hexahydrate is 8-12:1. The mass ratio of triethylenetetramine-graphene oxide and iron nitrate nonahydrate is 5-10:1. The mass ratio of triethylenetetramine-graphene oxide and polyethylene glycol 4000 is 1:2-5. The mass ratio of triethylenetetramine-graphene oxide and sodium acetate is 1:2-5.