Removal of cobalt and lead ions from wastewater samples using an insoluble nanosponge biopolymer composite: adsorption isotherm, kinetic, thermodynamic, and regeneration studies

Abstract

In this study, an insoluble nanosponge biopolymer composite was synthesized, using a combined process of amidation reaction, cross-linking polymerization, and sol-gel method to obtain a phosphorylated multiwalled carbon nanotube-cyclodextrin/silver-doped titania (pMWCNT-βCD/TiO₂-Ag). This work mainly emphasized on the removal of lead (Pb²⁺) and cobalt (Co²⁺) metal ions from synthetic and real wastewater samples using the synthesized pMWCNT-βCD/TiO₂-Ag as a biosorbent. The new material was characterized by Fourier transform infrared (FTIR) spectroscopy, zeta potential, Brunauer-Emmett-Teller (BET) method, and scanning electron microscopy (SEM). Adsorption studies for the model pollutants were performed in batch mode. The effect of the solution pH, adsorbent dosage and the presence of competiting ions were investigated. The isotherm, kinetic, thermodynamic, and regeneration studies were also undertaken. The ability of the new material to effectively remove Pb²⁺ and Co²⁺ from synthetic wastewater and mine effluent samples was tested. The maximum removal capacities achieved for the removal of Pb²⁺ and Co²⁺ from mine effluent sample were 35.86 and 7.812 mg/g, respectively.