Sequestration of Pb(II) Ions from Aqueous Systems with Novel Green Bacterial Cellulose Graphene Oxide Composite

In this study, a novel green adsorbent material prepared by the esterification of bacterial cellulose (BC) and graphene oxide (GO), richly containing hydroxyl, alkyl, and carboxylate groups was characterised by FTIR (Fourier Transform infrared spectroscopy), XRD (X-ray diffraction), SEM (Scanning electron microscopy) and TGA (Thermo-graphimetric analysis). The specific surface area (SSA) and pore size distribution (PSD) analysis of materials were also analysed. Batch experiments⁻adsorption studies confirmed the material to have a very high Pb²⁺ removal efficiency of over 90% at pH 6⁻8. Kinetic studies showed that the uptake of metal ions was rapid with equilibrium attained after 30 min and fitted well with the pseudo-second-order rate model (PSO). Isotherm results with a maximum adsorption capacity (Q_max) of 303.03 mg/g were well described by Langmuir's model compared to Freundlich. Desorption and re-adsorption experiments realised that both adsorbent and adsorbates could be over 90⁻95% efficiently recovered and reused using 0.1 M HNO₃ and 0.1 M HCl.