Synthesis of Amino-Functionalized Waste Wood Flour Adsorbent for High-Capacity Pb(II) Adsorption.

An innovative wood flour-based adsorbent for Pb(II) removal was synthesized via a cost-effective and environment-friendly method, which could be high on the priority list owing to its high absorption capacity. By increasing the specific surface and introducing functional groups through delignification and amination, the experimental adsorption capacity of the prepared adsorbent could reach 189.9 mg/g in 180 min (pH = 4, = 293 K, dosage = 1 g/L, and ion concentration = 300 mg/L). This value is higher than most of those achieved in previous studies on wood-based adsorbents. Pseudo-second-order and Langmuir models were utilized to describe the adsorption kinetics and isotherms, respectively. The effects of solution pH, adsorbent dosage, and temperature on the adsorption efficiency were also evaluated. With a low decrease rate of 20.2% in five cycles, the adsorbent possessed reusability. The adsorbents exhibited high selectivity in the Pb(II), Cu(II), and Zn(II) mixed solution, and the selectivity coefficient of adsorbents to Pb(II) could reach approximately 2.74 in triad. The method could prompt the development of cost-effective methods for the removal of heavy metals from wastewater.