▎ 摘　　要

NOVELTY - Preparing graphene oxide-magnetic nano particle-sludge composite adsorbent, involves (i) taking residual sludge, adjusting pH value, carrying out ultrasonic treatment, drying to constant weight, grinding and sieving to obtain sludge powder, (ii) taking 1-3 gram ferric chloride and 1-3 gram ferrous sulfate and adding into 10 mL of distilled water, and stirring to obtain an iron-containing solution. The 10-12 gram sludge powder is added into 100 mL distilled water, heated at constant temperature of 80-100degrees Celsius, then added an iron-containing solution, stirred for 30 minutes, adjusted the pH value to 10-11, then stirred for 40-60 minutes, carried out solid-liquid separation, washed the solid with deionized water, and dried to constant weight to obtain a residual sludge-magnetic nanoparticle composite. (iii) The graphene oxide is added into deionized water, carried out ultrasonic homogenization. USE - Method for preparing graphene oxide-magnetic nano particle-sludge composite adsorbent used for removing low-concentration antibiotics in water (claimed). Uses include but are not limited to aquaculture wastewater, medical wastewater, sewage treatment, plant drainage and garbage leachate treatment. ADVANTAGE - The method ensures subsequent re-modification and improve the effect of composite modification, and uses graphene oxide surface with negative electricity and has a large amount of functional groups such as carboxyl and epoxy groups for ultrasonic secondary modification, which enhance the removal ability of the adsorbent to the antibiotic in the water concentration not more than 50 mg/L and reaches more than 96 %. DETAILED DESCRIPTION - Preparing graphene oxide-magnetic nano particle-sludge composite adsorbent, involves (i) taking the residual sludge, adjusting the pH value, carrying out ultrasonic treatment, drying to constant weight, grinding and sieving to obtain sludge powder, (ii) taking 1-3 gram ferric chloride and 1-3 gram ferrous sulfate and adding into 10 mL distilled water, and stirring to obtain an iron-containing solution. The 10-12 gram sludge powder is added into 100 mL distilled water, heated at constant temperature of 80-100degrees Celsius, then added an iron-containing solution, stirred for 30 minutes, adjusted the pH value to 10-11, then continuously stirred for 40-60 minutes, carried out solid-liquid separation, washed the solid with deionized water, and dried to constant weight to obtain a residual sludge-magnetic nanoparticle composite. (iii) The graphene oxide is added into deionized water, carried out ultrasonic homogenization to prepare graphene oxide turbid liquid with the concentration of 0.5 mg/mL. The 10 gram sludge-magnetic nanoparticle compound is added into 100 mL distilled water, electromagnetically stirred for 10 minutes, added 10-20 mL graphene oxide suspension, performed ultrasonic treatment for 10-30 minutes, further performed solid-liquid separation, washed solids with deionized water, and dried to constant weight to obtain the magnetic nano-particle compound. INDEPENDENT CLAIMS are included for: (1) Use of the graphene oxide-magnetic nanoparticle- sludge composite adsorbent for removing low-concentration antibiotics in water. (2) A method for removing low-concentration antibiotics in water, which involves adding graphene oxide-magnetic nanoparticle- sludge composite adsorbent, placing mixture in a shaking table, shaking for 8 hours, and carrying out solid-liquid separation.