▎ 摘　　要

NOVELTY - Preparing adsorbent based on garden waste, comprises (i) ultrasonically cleaning and drying of garden waste are carried out to obtain dried garden waste, (ii) adding zinc acetate into anhydrous ethanol to obtain zinc acetate seed liquid, soaking garden waste into zinc acetate seed liquid for soaking treatment, taking out and drying, adding into a vacuum tubular furnace, introducing nitrogen to keep anaerobic condition for sintering to obtain zinc seed layer/biological carbon composite material, (iii) soaking the zinc seed layer/biochar composite material into the growth liquid with temperature of 70-85degrees Celsius to react for 3-4 hours, drying to obtain the zinc oxide (ZnO)/biochar composite material, (iv) adding graphene oxide and ZnO/biochar composite material into the chitosan solution, adding coagulant, placing at room temperature, washing with distilled water, performing vacuum freezing and drying. USE - The adsorbent is useful for water treatment under photocatalytic condition (claimed). ADVANTAGE - The adsorbent can treat a variety of organic pollutants and heavy metal pollutants, the degradation rate of organic pollutants bisphenol A or nitrophenol can reach 60-75%, and the removal rate of lead or cadmium is 60-72%.