High-efficient biosorbent of Pb2+ derived from the organic frameworks of Cladophora rupestris

Abstract

Abstract This study aims to investigate the Pb2+ adsorption performance of the organic frameworks derived from Cladophora rupestris (CROF). The characterizations of CROF and Pb2+ adsorption process was analysed using SEM-EDS, LPSA, BET, PHPZC, FTIR and XPS. The results was showed that CROF was porous structure, had both macroporous and microporous properties. The particle size is normally distributed with a median diameter of 36.8 µm. PHPZC of CROF was 7.02. The CROF adsorption isotherms and kinetics closely matched Langmuir model and Pseudo-second-order(PSO), respectively, the adsorption behaviors can be classified as monolayer chemical adsorption. The maximum adsorption capacity (Qm) was 15.02 mg/g and 97% of the Pb2+ was adsorbed onto the CROF within 20 min. And the adsorption was exothermic, spontaneous and minimised randomness. Additionally, the biosorbent has outstanding Pb2+adsorption capability due to pore filling, ion exchange, Pb-πinteraction, and surface complexation between nitrogen and oxygen functional groups(OFGs and NFGs). CROF is economical and environmentally friendly and it can be used as an adsorbent to take Pb2+ out from waterbodies.