Surface modification of cellulose by sequential metal-free photoinduced atom transfer radical polymerization and its application for aqueous Hg(II) removal

Cellulose-based polymer brush-on-brush composite adsorbent is prepared under simple and mild conditions via a four-step two sequential organophotocatalyzed atom transfer radical polymerization for the efficient removal of Hg(II) from aqueous media. The defined structure of the cellulose-based composites was supported by the characterization results. Influences of solution pH, temperature and adsorbent dosage on the adsorption behavior of the adsorbent were determined by batch experiments. The adsorption performance of the polymer brush composite intermediate was also investigated as a comparison to the final adsorbent to illustrate the significance of the topological surface structure on adsorption efficiency and capacity. Adsorption kinetics, isotherm and mechanism were studied systematically to further clarify the adsorption process. In addition, the adsorbent exhibits good applicability as it can be reused for 5 times without obvious decrease in desorption rate (>90 %), which showed potential utility for preconcentration and recovery of aqueous Hg(II).