▎ 摘　　要

NOVELTY - Composite bentonite comprises 50 pts. wt. bentonite and 0.5-2 pts. wt. graphene oxide. USE - Composite bentonite is useful for treating wastewater, preferably methylene blue wastewater (all claimed). ADVANTAGE - The composite bentonite can be synthesized by a simple and economical method, can be used conveniently, is environmentally-friendly, and is excellent in adsorption of organic dyes. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of composite bentonite, which involves ultrasonically dispersing bentonite in water to obtain a uniform suspension of bentonite, ultrasonically dispersing graphene oxide in water to obtain a homogeneous solution of graphene oxide, mixing the bentonite suspension and graphene oxide suspension, centrifugally dehydrating, washing, and drying; and (2) usage method of composite bentonite in wastewater treatment, which involves adding composite bentonite as adsorbent to methylene blue wastewater, vibrating at room temperature, and centrifugally separating wastewater and adsorbent.