Abstract：In order to clarify the removal effect and mechanism of Pb²⁺from water, the nano zero-valent iron (NZVI) was prepared by the method of liquid phase reduction. NZVI was prepared by liquid phase reduction with addition of organic polymer material. The characteristics of NZVI was investigated using scanning electron microscope (SEM) and X-ray diffraction (XRD) . The experiment was conducted to investigate the influence of initial ion concentration and solution initial p H value on removal of Pb²⁺with time changing, and clarify the removal effect and mechanisms of Pb²⁺from water using NZVI. The results show that the reaction equilibrium achieves within 120 min and the removal rate of Pb²⁺is more than 99% when the Pb²⁺initial concentration is 50 and 100mg/L and the addition of NZVI is 1 g/L. The removal ratio of Pb²⁺increased from 41.47% to 73.58% while solution initial p H value increase from 2 to 3, and from 73.58% to 92.62% initial p H value from 3 to 4. The results also indicate that the removal of Pb²⁺by NZVI is suitable for pseudo second-order model and it is mainly conducted by the redox reaction and co-precipitation.

Keywords: nano zero-valent iron; Pb²⁺; redox reaction; reaction dynamics