▎ 摘　　要

NOVELTY - A composite adsorbent comprises polyethyleneimine-modified graphene oxide substrate and L-dopamine-modified ferroferric oxide nanoparticles bonded to the substrate. USE - Composite adsorbent is used for removing hexavalent chromium from wastewater (claimed). ADVANTAGE - The composite adsorbent can be prepared by simple process under mild reaction condition, and enables rapid separation of hexavalent chromium from wastewater. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of composite adsorbent, which involves modifying graphene oxide with polyethyleneimine, preparing L-dopamine-modified ferroferric oxide nanoparticles and bonding L-dopamine-modified ferroferric oxide nanoparticles on the modified graphene oxide; and (2) use of composite adsorbent for removing hexavalent chromium from wastewater.