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A novel polyaniline-modified CNT and graphene-based nanocomposite (2.32–7.34 nm) was prepared and characterized by spectroscopic methods. The specific surface area was 176 m2/g with 0.232 cm3/g as the specific pore volume. The nanocomposite was used to remove zinc and lead metal ions from water; showing a high removal capacity of 346 and 581 mg/g at pH 6.5. The data followed pseudo-second-order, intraparticle diffusion and Elovich models. Besides this, the experimental values obeyed Langmuir and Temkin isotherms. The results confirmed that the removal of lead and zinc ions occurred in a mixed mode, that is, diffusion absorption and ion exchange between the heterogeneous surface of the sorbent containing active adsorption centers and the solution containing metal ions. The enthalpy values were 149.9 and 158.6 J.mol−1K−1 for zinc and lead metal ions. The negative values of free energies were in the range of −4.97 to −26.3 kJ/mol. These values indicated an endothermic spontaneous removal of metal ions from water. The reported method is useful to remove the zinc and lead metal ions in any water body due to the high removal capacity of nanocomposite at natural pH of 6.5. Moreover, a low dose of 0.005 g per 30 mL made this method economical. Furthermore, a low contact time of 15 min made this method applicable to the removal of the reported metal ions from water in a short time. Briefly, the reported method is highly economical, nature-friendly and fast and can be used to remove the reported metal ions from any water resource.

The present work is aimed at developing an effective graphene-based sorbent for liquid-phase sorption of organic pollutants from aquatic media. The material synthesized in accordance with the metho...

The prospect of using nanostructured materials in sorption-desorption cycles is substantiated by their unique physical-chemical characteristics determining the performance properties of modern sorb...

Nowadays, the removal of the rare-earth elements in water and hydrogeosystems is an urgent issue. Therefore, graphene oxide / polyhydroquinone nanocomposite was used to remove samarium ions (Sm3+) in aqueous solutions. The sorption and desorption of Sm3+ ions on the graphene oxide / polyhydroquinone nanocomposite from aqueous solutions are studied with contact time (15.0 min.), initial concentration (100.0 mg/L), the weight of sorbent (0.3 g/L), pH of a solution (6.0) and temp. (25C°). The rate constants of sorption, equilibrium sorption capacity, percentage sorption and desorption, entropy and enthalpy of Sm3+ extraction process are discussed. The analysis of the proceed mechanisms is conducted with the kinetic dependences and sorption isotherms, for which reason the empirical equations of pseudo-first and pseudo-second-order, Elovich and intraparticle diffusion, as well as the equations of Langmuir, Freundlich, Temkin, Dubinin-Radushkevich were used. It should be noted that the absorption of Sm3+ proceeded according to the mixed diffusion mechanism and is controlled by the interactions among the sorbent and the functional groups of the sorbent. According to Langmuir's model, the maximum sorption capacity of the developed sorbent was 357.14 mg g−1. Thus, the high efficiency of the developed sorbent for the purification and remediation of hydrogeosystems for samarium ions is useful. The reported method may be used for the removal of 360 million tons of wastewater with rare earth elements including samarium ions.