A novel amino modified starch (AMS）adsorbent modified with ethylenediamine was obtained via grafting polymerization and ring-opening reactions using cassava starch as raw material.The adsorbent was characterized by FT-IR

XRD and SEM.The absorption performance and adsorption thermodynamics were studied in the adsorption process of Pb(Ⅱ）ions in aqueous solution on the AMS.The effects of pH value

adsorption time

temperature and initial concentration were investigated.It is found that the effect of pH on the adsorption is significant.The adsorption is fast and follows a pseudo-second order process.Chemical adsorption is the main process and the equilibrium isotherm is well described by the Langmuir model rather than the Freundlich model.The separation factors are in the range of 0—1.The maximum adsorption capacity of 0.481 mmol·g-1 is obtained at initial concentration of 100 mg·L-1

pH 6.0 and 25℃.The adsorption is a spontaneous and endothermic process with increased entropy

and higher temperature will benefit the adsorption.The adsorbent can be reused for more than five cycles without decreasing its adsorption efficiency.