▎ 摘　　要

NOVELTY - Preparing adsorbent, comprises e.g. adding 3 pts. wt. pre oxidized graphite solid to 69 pts. vol. concentrated sulfuric acid, stirring for 10-15 minutes, adding 9 pts. wt. potassium permanganate under stirring conditions, ensuring temperature of reaction at below 10 degrees C, incubating for 30-50 minutes, dispersing to obtain preoxidized graphene suspension, heating at 33-38 degrees C, adding 60-70 pts. vol. water, under stirring conditions within 7 minutes, adding 3 pts. wt. microcrystalline cellulose and reacting for 30-60 minutes to obtain mixture of graphene oxide and nanocrystalline cellulose. USE - The adsorbent is useful for treating wastewater containing dye, preferably cationic dye, anionic dyes and nonionic dye ( all claimed). ADVANTAGE - The adsorbent is greatly improved and absorbs less than 100 mg/l dye concentration. The method is simple and easy to operate. DETAILED DESCRIPTION - Preparing adsorbent, comprises (i) adding 3 pts. wt. pre oxidized graphite solid to 69 pts. vol. concentrated sulfuric acid, stirring for 10-15 minutes, adding 9 pts. wt. potassium permanganate under stirring conditions, ensuring temperature of reaction at below 10 degrees C, incubating for 30-50 minutes, dispersing uniformly to obtain preoxidized graphene suspension, (ii) heating step (i) preoxidized graphene suspension at 33-38 degrees C, adding 60-70 pts. vol. water, under stirring conditions within 7 minutes, adding 3 pts. wt. microcrystalline cellulose, reacting for 30-60 minutes to obtain mixture of graphene oxide and nanocrystalline cellulose, carrying out filtering in hot condition after the completion of reaction, simultaneously washing the filter cake with water until neutral and drying.