Single-step fabrication of recyclable microporous hyperbranched polyethyleneimine adsorbent with highly efficient and selective removal of lead ions

A novel recyclable hyperbranched adsorbent for selective adsorption of Pb2+ ions is fabricated by a facile single-step crosslinking reaction. The as-synthesized adsorbent has porous structure and large of amino groups which beneficial for the removal of Pb2+ ions in aqueous solution and the removal efficiency is 99.2%. The result also indicates that adsorption ability of the obtained adsorbent increased with the increase of pH from 1 to 6 and temperature from 278 K to 308 K, respectively. The adsorption process of Pb2+ ions onto PPEI-2-AG followed the Langmuir isotherm model, and a kinetic study indicates that the process fitted pseudo-second order model well. The removal of Pb2+ ions by PPEI-2-AG is mainly controlled by the specific interactions between Pb2+ ions and amino functional groups, which could be further confirmed by X-ray photoelectron spectroscopy (XPS). The results demonstrate that PPEI-2-AG holds high potential in environmental remediation.