Phosphate-crosslinked β-cyclodextrin polymer for highly efficient removal of Pb() from acidic wastewater

The efficient and green separation of heavy metal ions from acidic wastewater is a challenging industrial problem. In this work, a novel acidic adsorbent, β-cyclodextrin phosphate polymer (β-CDPP), was synthesized by one-pot method. The β-CDPP was characterized by FT-IR, SEM, EDS, and XPS. The β-CDPP can effectively remove more than 95% Pb( ii ) from acidic wastewater (pH = 3). The adsorption of Pb( ii ) reached equilibrium in 20 min, and the maximum Pb( ii ) adsorption capacity calculated by the Sips isotherm model was as high as 576.92 mg g −1 . FT-IR and XPS analysis revealed that the adsorption mechanism of Pb( ii ) depends on the chelating effect and electrostatic interaction. The adsorbent showed good reusability evidenced by eight cycles of adsorption/desorption experiments. Meanwhile, the low concentration of Na( i ), K( i ), and Ca( ii ) had little effect on the adsorption of Pb( ii ). Moreover, the adsorbent can effectively remove a variety of mixed heavy metals from acidic wastewater including Pb( ii ), Cu( ii ), Cd( ii ), Zn( ii ), Co( ii ), and Ni( ii ). The results indicate that β-CDPP is a promising candidate for the deep treatment of acidic heavy metal-contained wastewater. Novel phosphate-crosslinked β-cyclodextrin polymer was synthesized for highly efficient Pb( ii ) removal from acidic wastewater.