▎ 摘　　要

NOVELTY - Preparing fast sedimentation sewage treatment agent comprises (1) adding imidazole and sodium hydroxide into dimethyl sulfoxide, stirring at uniform speed of 55-60℃ for 1 hour, adding 1,2-dichloroethane dropwise, continuously stirring the insulation for 2 hours after the dropwise addition, cooling to room temperature after the stirring, adding deionized water and refrigerating at 0-5℃ for 10 hours, recrystallizing, suction filtering with deionized water, and drying to obtain composite a, (2) adding the foamed graphene oxide into deionized water, and washing to obtain modified foamed graphene oxide, (3) mixing the modified foamed graphene oxide and composite a, and obtaining modified foamed graphene, (4) adding the modified graphene foam into acetonitrile, and (5) adding graphene derivatives into acetonitrile, slowly adding anhydrous ferric chloride, stirring and reacting, filtering, washing with ethyl acetate three times, and drying to obtain sewage treatment agent. USE - The method is useful for removing heavy metal in waste water by flocculation, absorption, accumulation and enrichment of microorganism or plant. ADVANTAGE - The method enables to prepare fast sedimentation sewage treatment agent, which can change its space volume under the condition of not changing shape, contains more molecules or ions, which is used for absorbing small molecule organic pollutant, introduces the iron salt can be used as inorganic flocculating agent, and processes the sewage. DETAILED DESCRIPTION - Preparing fast sedimentation sewage treatment agent comprises (1) adding imidazole and sodium hydroxide into dimethyl sulfoxide, stirring at uniform speed of 55-60℃ for 1 hour, adding 1,2-dichloroethane dropwise, continuously stirring the insulation for 2 hours after the dropwise addition, cooling to room temperature after the stirring, adding deionized water and refrigerating at 0-5℃ for 10 hours, recrystallizing, suction filtering with deionized water, and drying to obtain composite a, (2) adding the foamed graphene oxide into deionized water, stirring at constant speed for 15 minutes to prepare the dispersion, adding (3-chloropropyl)triethoxysilane into absolute ethanol, stirring at constant speed for 5 minutes, adding it to the dispersion, ultrasonically stirring for 30 minutes, adding dropwise 10% dilute hydrochloric acid to adjust the pH until pH is 4-5, keeping the temperature at 50℃ for 2 hours, raising the temperature to 65℃, continuously reacting for 2 hours, cooling to room temperature after the reaction is finished, centrifuging, and washing to obtain modified foamed graphene oxide, (3) mixing the modified foamed graphene oxide and composite a, adding benzene, raising the temperature to 110℃, refluxing reaction for 24 hours, cooling to room temperature after the reaction, washing three times with benzene, dimethyl sulfoxide and absolute ethanol, drying 10 hours at 55℃ afterwards, and obtaining modified foamed graphene, (4) adding the modified graphene foam into acetonitrile, raising the temperature to 70℃ under nitrogen atmosphere, slowly adding n-chlorobutane dropwise, insulating, stirring and reacting for 12 hours, cooling to room temperature after the reaction, filtering, washing with ethyl acetate for three times, and drying to obtain graphene derivatives, and (5) adding graphene derivatives into acetonitrile, slowly adding anhydrous ferric chloride, stirring and reacting at 50℃ for 12 hours, filtering, washing with ethyl acetate three times, and drying to obtain sewage treatment agent. An INDEPENDENT CLAIM is also included for fast sedimentation sewage treatment agent prepared by the preparation method.