Metal ion sorption by chitosan–tripolyphosphate beads

Abstract

Heavy metal removal from wastewater is crucial for the proper management of discharged water from mining operations. This residual water is typically unusable for other purposes such as for human/animal, crop, or industrial consumption. Eco‐friendly adsorption materials are necessary to ensure the sustainable treatment of this wastewater. Therefore, the sorption of Cu(II), Cd(II), Pb(II), and Zn(II) ions onto chitosan–tripolyphosphate (CTPP) beads was investigated using real mining wastewater and prepared ion metal solutions. The effects of pH, contact time, temperature, selectivity, and maximum sorption capacity in successive batches at different concentrations were studied. The optimum sorption of cations, except for copper (pH 3) was found at pH 5. Equilibrium in the adsorption of all metals was reached at 24 h of contact. Studies of the maximum sorption capacity at different concentrations showed that the CTPP beads could adsorb 158, 55, 47, and 47 mg/g of Pb(II), Cu(II), Cd(II), and Zn(II), respectively. Experimental data for the sorption of Pb(II) were optimally correlated with the Langmuir model. The thermodynamic parameters such as the changes in enthalpy (ΔH0), entropy (ΔS0), and free energy (ΔG0) were determined. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45511.

A study of the structural changes in a chitosan matrix produced by the adsorption of copper and chromium ions

“…As can be seen in Table 1, there exist clear differences in the adsorption of the metal ions by the chitosan films in the conditions above-described. The sorption capacity values measured in this work are in good agreement with those reported in studies of heavy metal ions adsorption by chitosan (Schmuhl, Krieg and Keizer, 2001;Bailey, Olin, Bricka and Adrian, 1999;Giraldo, Rivas, Elgueta and Mancisidor, 2017).…”

Synthesis and adsorption characteristics of grafted hydrazinyl amine magnetite-chitosan for Ni(II) and Pb(II) recovery

“…The highest polarizability of Pb(II) makes these ions preferentially bound to ligands containing N as donor atoms (like in the hydrazinyl group). Giraldo et al [69] explain the better sorption of Pb(II) over Cu(II) , Cd(II) and Zn(II) metal cations on gelatin/activated carbon beads by its highest ionic radius, while Yang et al correlates the better affinity of thiourea/hypercrosslinked polystyrene for Pb(II) over Cd(II) and Cu(II) to the smallest hydrated radius [70]. Figure 7 shows the fits of sorption isotherms with the Langmuir, the Freundlich and the Sips equations.…”

Efficient removal of uranium, cadmium and mercury from aqueous solutions using grafted hydrazide-micro-magnetite chitosan derivative

“…The binding mechanisms are based on the reactivity of the same functional groups as those found on resins: chelation and ion-exchange mechanisms occur on naturally present reactive groups or on grafted moieties. Chitosan (obtained by partial deacetylation of chitin, one of the most abundant polysaccharide) has received a great attention because of its hydrophilic nature and the presence of amine functions [26]: metal cations can be bound by chelation on lone electron pair of nitrogen in near-neutral solutions, while metal anions can be sorbed onto protonated amine groups in acidic solutions [27][28][29]. Metal transfer is controlled by the resistance to intraparticle diffusion because the polymer is poorly porous; this makes necessary modifying its structure by manufacturing hydrogels with expanded structure [30,31].…”