Nonlinear Isotherm and Kinetic Modeling of Cu(II) and Pb(II) Uptake from Water by MnFe2O4/Chitosan Nanoadsorbents

Abstract

Researchers are in continuous search of better strategies to minimize, if not prevent, the anthropogenic release of toxic heavy metals, such as Cu(II) and Pb(II), into drinking water resources and the natural environment. Herein, we report for the first time the low-temperature combustion synthesis of magnetic chitosan-manganese ferrite in the absence of toxic cross-linking agents and its removal of Cu(II) and Pb(II) from single-component metal solutions. The nonlinear Langmuir model best described the isotherm data, while the nonlinear pseudo-second order model best described the kinetic data, signifying monolayer Cu(II) or Pb(II) adsorption and chemisorption as the rate-determining step, respectively. Adsorption capacities by magnetic chitosan-manganese ferrite obtained for both metals were consistently higher than those by manganese ferrite, indicating that chitosan enhanced the performance of the magnetic adsorbent. The maximum adsorption capacities of magnetic chitosan-manganese ferrite for Cu(II) and Pb(II) were 14.86 and 15.36 mg g−1, while that of manganese ferrite were 2.59 and 13.52 mg g−1, respectively. Moreover, the adsorbents showed superior binding affinity and sorption for Pb(II) than Cu(II) owing to the stronger ability of the former to form inner-sphere complexes with manganese ferrite and magnetic chitosan-manganese ferrite. Finally, thermodynamic studies revealed that the uptake of either Pb(II) or Cu(II) by magnetic chitosan-manganese ferrite was spontaneous and endothermic. The as-prepared adsorbent was characterized for morphology, elemental composition, surface functional sites, and particle size using scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and dynamic light scattering technique, respectively.

Removal of Toxic Copper Ion from Aqueous Media by Adsorption on Fly Ash-Derived Zeolites: Kinetic and Equilibrium Studies

“…In addition, the fundamental characteristic and practicability of the Langmuir isotherm regarding a dimensionless constant separation factor or equilibrium parameter, R L , suggest that the adsorption process of Cu 2+ using the prepared material was favorable, Figure 6, in accord with literature [43]. olymers 2021, 13, x suggest that the adsorption process of Cu 2+ using the prepared material was favo Figure 6, in accord with literature [43].…”

Modified magnetic chitosan materials for heavy metal adsorption: a review

“…Taguba et al synthesized magnetic chitosan—manganese ferrite (CMFO) by simple low-temperature combustion technology without a toxic crosslinking agent. 90 The surface of CMFO is rough, and agglomerated particles appear. The maximum adsorption capacity of Cu on CMFO is 14.86 mg g −1 , and the adsorption process is spontaneous and endothermic, which is consistent with the Langmuir model.…”

Simultaneous Removal of Heavy Metals (Cu, Cd, Cr, Ni, Zn and Pb) from Aqueous Solutions Using Thermally Treated Romanian Zeolitic Volcanic Tuff

“…The n value indicates a normal adsorption when n < 1, cooperative adsorption when n > 1 and a favorable adsorption when 1< n < 10 [45]. PFO, proposed by Lagergren, assumes physical adsorption as the rate-controlling mechanism, while PSO assumes that the chemisorption controls the reaction rate [46][47][48].…”