Novel modified microcrystalline cellulose-based porous material for fast and effective heavy-metal removal from aqueous solution

A novel porous adsorbent with high surface area and rigid structure was prepared by crosslinking oxidized microcrystalline cellulose particles with tetrafluoroterephthalonitrile. N₂ adsorption–desorption measurements revealed the surface area to be 88.32 m² g⁻¹ for the porous adsorbent, while it was only 25.74 m² g⁻¹ for the sample crosslinked using epichlorohydrin. This porous adsorbent showed excellent performance for fast and efficient removal of low-concentration heavy metals from aqueous solution. Adsorption kinetic study demonstrated that, within 5 min, the removal efficiency for Pb²⁺, Cu²⁺, and Cd²⁺ with initial concentration of 10 mg L⁻¹ by this adsorbent was 93.2, 87.5, and 72.3 %, respectively. Moreover, the pseudo-second-order model correlated better to the adsorption kinetic data than the pseudo-first-order model. The effects of other factors, e.g., initial solution pH, adsorption temperature, initial metal concentration, and background electrolytes, on the removal efficiency were also analyzed. Additionally, desorption experiments indicated that this adsorbent could be effectively regenerated using dilute HCl solution.