▎ 摘　　要

NOVELTY - Preparing a lead ion composite adsorbent involves preparing chitosan acetic acid solution and graphene oxide acetic acid dispersion, adding the graphene oxide acetic acid dispersion into the chitosan acetic acid solution dropwise, adding lead salt with constant magnetic stirring under the condition of 60 degrees C to the mixed solution, stirring to dissolve for 3 hours to form a homogeneous mixture, allowing to rest for 6 hours. The mixed solution is added dropwise into 2 mol/L sodium hydroxide coagulation solution with a syringe to form a ball and solidified for 3-4 hours to form microspheres which are taken out and washed until neutral. The washed microspheres are transferred to glutaraldehyde aqueous solution, stirred, allowed to react at 30 degrees C for 30-180 minutes and then washed with anhydrous ethanol and deionized water in order to remove unreacted glutaraldehyde. The washed microspheres are transferred to the elution solution, shaken at 30 degrees C for 30 minutes to elute lead cation Pb2+. USE - Method for preparing a lead ion composite adsorbent used for treatment of waste water containing lead ion. ADVANTAGE - The composite adsorbent is a millimeter-level gel microsphere with regular shape, well-developed pore structure and uniform particle size distribution, which has good adsorption and selectivity for Pb2+, can be recycled and reused, and its preparation process is simple, energy consumption is low, and it is environmentally friendly. DETAILED DESCRIPTION - Preparing a lead ion composite adsorbent involves preparing chitosan acetic acid solution and graphene oxide acetic acid dispersion, adding the graphene oxide acetic acid dispersion into the chitosan acetic acid solution dropwise, adding lead salt with constant magnetic stirring under the condition of 60 degrees C to the mixed solution, stirring to dissolve for 3 hours to form a homogeneous mixture, allowing to rest for 6 hours. The mixed solution is added dropwise into 2 mol/L sodium hydroxide coagulation solution with a syringe to form a ball and solidified for 3-4 hours to form microspheres which are taken out and washed until neutral. The washed microspheres are transferred to glutaraldehyde aqueous solution, stirred, allowed to react at 30 degrees C for 30-180 minutes and then washed with anhydrous ethanol and deionized water in order to remove unreacted glutaraldehyde. The washed microspheres are transferred to the elution solution, shaken at 30 degrees C for 30 minutes to elute lead cation Pb2+. The elution process is repeated 4-6 times and finally the microspheres are washed until neutral. The microspheres are dried to obtain the lead ion imprinted graphene oxide/chitosan composite adsorbent.