▎ 摘　　要

NOVELTY - Method for absorbing copper ion in sewage involves (a) preparing nitrogen-doped graphene aerogel, (b) preparing nitrogen-doped graphene hydrogel paper electrode, (c) placing prepared heavy metal ion solution in an electric adsorption vessel, subjecting the nitrogen-doped graphene aerogel paper electrode to electric adsorption, and monitoring the change in the conductivity of the solution in real time, and (d) removing voltage on the electrode, restoring the conductivity of the solution, and performing desorption regeneration of the electrode. USE - The method is useful for absorbing copper ion in sewage (claimed). ADVANTAGE - The method is simple, easy, rapid, and environmentally-friendly. DETAILED DESCRIPTION - Method for absorbing copper ion in sewage involves (a) preparing nitrogen-doped graphene aerogel by ultrasonically dispersing oxidized graphene in deionized water for 10-30 minutes, adding urea, mechanically stirring the mixture for 15 minutes, pouring the mixed solution into a hydrothermal reactor, then placing the hydrothermal reactor in muffle furnace, heating at 180 degrees C for 12 hours, completing the reaction, soaking the product in distilled water for 2-3 days, and freeze-drying the material, (b) preparing nitrogen-doped graphene hydrogel paper electrode by uniformly mixing prepared nitrogen-doped graphene aerogel with prepared polyvinyl alcohol solution to form paste-like dispersion, removing 0.1-0.4 ml dispersion liquid, uniformly coating on cardboard, and drying, (c) placing prepared heavy metal ion solution in an electric adsorption vessel, subjecting the nitrogen-doped graphene aerogel paper electrode to electric adsorption reaction, performing electron adsorption heavy metal ion experiment using three electrode system, where the paper electrode is working electrode, platinum electrode is counter electrode, and calomel electrode is the reference electrode, and simultaneously using the conductivity meter to monitor the change in the conductivity of the solution in real time, where when the conductivity remains constant it indicates nitrogen-doped graphene aerogel paper electrode absorption is balanced, and (d) removing voltage on the electrode, restoring the conductivity of the solution near the initial value, and performing desorption regeneration of the electrode.