Radiation-induced grafting of 4-vinyl pyridine onto cellulose microsphere for Cr(Ⅵ) removal

摘要

A novel a mino-functionalized cellulose microsphere adsorbent (named C-VP) was prepared by radiation-induced grafting 4-vinyl pyridine (4VP) onto cellulose microsphere and subsequent protonation process. The graft polymerization conditions on the influence of grafting yield such as total absorbed dose, dose rate, solvent mixture ratio and monomer concentration, have been studied in detail. The obtained C-VP was tested for the abilities to remove Cr(VI) in batch experiments. The results demonstrated that the Cr(VI) adsorption was highly pH dependent and the maximum Cr(VI) uptake was obtained as the pH of solvent was 2.74. The adsorption isotherms of the C-VP for Cr(VI) fit the Langmuir model. The adsorption rate was considerably fast, and the adsorption reached equilibrium within 25 min. In addition, the Cr(VI) ions could be effectively desorbed using a 0.1 mol L-1 NaOH solution. Moreover, the reusability of the obtained C-VP was tested for several times and only slight loss in adsorption capacity was observed. Our work demonstrated the as-prepared adsorbent could possess a promising potential in the practical field of water treatment.