Dynamic adsorption of Cd2+ from aqueous solution using biochar of pine-fruit residue

The present investigation describes the applicability of biochar of pine-fruit residue (PFR) as a novel adsorbent for Cd2+ adsorption in the packed-bed system. Biochar was characterised for surface properties using BET surface area, Boehm titration, FT-IR and a scanning electron microscopy (SEM). Experiments were performed to investigate the influence of operational parameters such as bed height (Z = 5, 10 and 20 cm), metal-ion concentration (Co= 25, 50 and 100 mg · L−1) and flow-rate (Q= 2, 5 and 10 mL · min−1) on Cd2+ uptake capacity (qexp). Maximum qexp of 17.93 mg · g−1 corresponding to 51.90% of Cd2+ removal was obtained for Z = 5 cm, Co= 50 mg · L−1, Q = 2 mL · min−1 at pH 6.9 and 303 K. Established Thomas and Yoon-Nelson models were used to analyse experimental data and the model parameters were evaluated. The comparative study of error functions of Cd2+ adsorption capacity predicted by model showed that Thomas model is the best fit. The sorption efficiency of regenerated biochar in successive sorption–desorption cycles was 38.96% at the end of the third cycle. © 2019, © 2019 Indian Institute of Chemical Engineers.