Individual and simultaneous adsorption of Ni (II), Cd (II), and Zn (II) ions over polyamide resin: Equilibrium, kinetic and thermodynamic studies

Abstract

Heavy metal pollution is a serious environmental issue worldwide with rapid increase in global industrial activities (Podder and Majumder [2016]: Water Conserv Sci Eng 1, 103–125). In this study, aromatic polyamide (PA) containing the azomethine group (Vidhyadevi et al. [2012]: Sep Sci Technol 48, 1450–1458) was used as an adsorbent for the individual and simultaneous adsorption of Ni (II), Cd (II), and Zn (II) ions from their aqueous solutions. Equilibrium, kinetic, and thermodynamic analyses of Ni (II), Cd (II), and Zn (II) ions adsorption were also carried out. The kinetic study on heavy metal ions adsorption suggests that the adsorption follows pseudo‐second‐order kinetic model. The thermodynamic study results revealed that the process is spontaneous and exothermic in nature. In the multicomponent adsorption system, adsorption of one metal ion was considerably reduced by the presence of other ions in the solution due to competition for the active sites on PA. The adsorption of heavy metal ions over PA was confirmed through FT‐IR, SEM, and EDX analyses. The adsorption capacity of PA was found significantly higher than other adsorbents. The PA could be regenerated and reused even after five cycles for the Ni (II), Cd (II), and Zn (II) ions suggesting that adsorption using the PA is a reversible process. Significance of the present work Polyamide resin (PA) is an effective adsorbent for the individual and simultaneous removal of Ni (II), Cd (II), and Zn (II). Maximum adsorption capacity of PA for Ni (II), Cd (II), and Zn (II) ions were found to be better than other commonly used adsorbents. Repeated desorption studies indicate that the PA may be reused and the adsorption is a reversible process. Adsorption mechanism of metal ions over PA is explained. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S340–S351, 2019

Synthesis of polyamide 6/nano-hydroxyapatite hybrid (PA6/n-HAp) for the sorption of rare earth elements and uranium

“…The pH-drift method [65] was used for quantifying the pH PZC of the materials. A fixed amount of sorbent (i.e., 100 mg) was distributed in a series of flasks (25 mL aqueous solutions, Polyamide-based materials [32][33][34] and soluble eggshell membrane protein-based nanocomposites adsorbents [35,36] have been successfully tested for the recovery of metal ions, including uranium [15,37] and rare earths [38]. However, the sorption capacities were usually low (in the range 0.5− 0.62 mmol g − 1 for Er(III), Tb(III) and Dy(III)) with optimum sorption close to pH 5, or about 0.08 mmol U g − 1 at pH 7 [39].…”

Enhanced heavy metal removal from an aqueous environment using an eco-friendly and sustainable adsorbent

“…4 b presents the plot of ( t / q t ) versus t in the linear pseudo-second-order model. The magnitudes of the adsorption capacities (357.29 mg/g for Zn(II), 458.32 mg/g for Cd(II), 208.12 mg/g for Hg(II)) according to this model were found to be very close to the experimental q max–cal values of 366.83 mg/g for Zn(II), 471.23 mg/g for Cd(II), and 205.11 mg/g for Hg(II).and the R 2 values were 0.9947, 0.9926, and 0.9956 for Zn(II), Cd(II) and Hg(II), respectively (Table 2 ), all close to 1.0, which suggests that the pseudo-second-order model fit the adsorption process well 61 . In Fig.…”

Bipyridine containing poly(amic-acid)s: Synthesis, characterization, and sorption behavior toward the Ni (II) ions

“…18 This is attributed to their high surface area, moderate chemicals, physical and mechanical stability, as well as the possibility to control the pore sizes during the polymerization. 19,20 The introduction of various chelating groups like pyrazol, 21 piperazine, 22 phenanthroline, 23 and imidazole 24 into a polymeric skeleton begins to make a polymeric sorbent to trap organic and inorganic pollutants. Moreover, they could be easily filtrated and regenerated using mild acidic or alkaline conditions.…”

“…18 This is attributed to their high surface area, moderate chemicals, physical and mechanical stability, as well as the possibility to control the pore sizes during the polymerization. 19,20…”