Zinc acetate (ZA) was applied as amodifier of reed activated carbon (AC) by phosphoric acid activation. The physical and chemical characteristics of modified activated carbon (AC-ZA) were analyzed, in comparison with traditional phosphoric acid AC. Zn (II) was presented at the surface of the modified adsorbent, which made AC-ZA react with amoxicillin (AMX) on various mechanisms and with high efficiency. The surface of AC became smoother and mesoporous after ZA-modification. The adsorption process for both absorbents conformed to the pseudo-second-order kinetics model, and for AC-ZA, Langmuir isotherm equation described the adsorption process better than Freundlich isotherm. The results of pH and ionic strength experiments showed that the adsorption ability of AC-ZA (76%) to AMX was 2.8 times as much as that of AC (27%) in neutral condition and the predominant adsorption mechanism was inner-sphere complexation. The decarboxylation process on AMX molecules promoted the combination. (C) 2020 Elsevier B.V. All rights reserved.