▎ 摘　　要

NOVELTY - The preparation method of carboxylated graphene/ferroferric oxide nanocomposite adsorbent involves dissolving graphene oxide in diethylene glycol to obtain solution (A), dissolving anhydrous ferric chloride and sodium acetate in diethylene glycol to obtain solution (B), mixing solution (A) and solution (B), uniformly stirring, and ultrasonically treating the mixed solution, transferring the treated mixed solution to a hydrothermal reactor, reacting, cooling, washing, transferring the precipitate to a vacuum oven, drying to obtain graphene oxide/ferroferric oxide powder. USE - Preparation of carboxylated graphene/ferroferric oxide nanocomposite adsorbent for treating chromium-containing tanning wastewater. ADVANTAGE - The environmentally-friendly method enables the preparation of carboxylated graphene/ferroferric oxide nanocomposite adsorbent by simple process, without adding flocculant, sodium hydroxide, and other chemical materials. DETAILED DESCRIPTION - The preparation method of carboxylated graphene/ferroferric oxide nanocomposite adsorbent involves (i) dissolving 0.075-0.085 part mass graphene oxide in 27.0-28.0 parts mass diethylene glycol to obtain solution (A), dissolving 0.30-0.35 part mass anhydrous ferric chloride and 0.55-0.65 part mass sodium acetate in 66.0-67.0 parts mass diethylene glycol to obtain solution (B), mixing solution (A) and solution (B), uniformly stirring, and ultrasonically treating the mixed solution, transferring the treated mixed solution to a 100 ml hydrothermal reactor, reacting at 220 degrees C for 6 hours, cooling to room temperature, washing the product with deionized water and absolute ethanol for 3-5 times, transferring the precipitate to a vacuum oven, drying at 40 degrees C to obtain graphene oxide/ferroferric oxide powder, (ii) ultrasonically dispersing 0.10-0.15 part mass graphene oxide powder in 100-105 parts mass deionized water, adding 10-12.0 parts mass sodium hydroxide and 8.0-10.0 parts mass monochloroacetic acid, mechanically stirring, ultrasonically treating in an ice bath, reacting for 2 hours, centrifugally washing the reaction product with deionized water and absolute ethanol for 3-5 times, transferring the precipitate to a vacuum oven, and drying at 40 degrees C.