Highly efficient removal of toxic Pb2+ from wastewater by an alginate–chitosan hybrid adsorbent

Abstract BACKGROUND In this study, a low‐cost and environment‐friendly alginate–chitosan hybrid adsorbent (depicted as Alg‐Chi) was developed for the removal of Pb2+ from water. RESULTS Experimental results showed that the Alg‐Chi exhibits high selectivity and affinity for Pb2+. The selectivity coefficients of the Alg‐Chi for Pb2+/Cr3+, Pb2+/Co2+ Pb2+/Cd2+, Pb2+/Zn2+, and Pb2+/Cu2+ are all >5. It can uptake 96.8% of Pb2+ from Pb2+‐containing solutions (1.5 mmol L−1), and the maximum adsorption capacity for Pb2+ reaches 468.5 mg g−1, which is higher than that of most reported adsorbents for Pb2+. Moreover, the Alg‐Chi can also be regenerated via simple acid elution and used repeatedly without loss in adsorption ability. CONCLUSIONS Analysis of the adsorption mechanism indicated that the Alg‐Chi adsorbed Pb2+ mainly through ion exchange and chemical coordination. Green and low‐cost raw materials, simple preparation process, efficient removal efficiency and recyclable, these characteristics give the synthetic Alg‐Chi broad application prospects in the field of Pb2+‐containing wastewater treatment. © 2018 Society of Chemical Industry