Magnetic adsorption separation process: an alternative method of mercury extracting from aqueous solution using modified chitosan coated Fe₃O₄ nanocomposites

Abstract

BACKGROUND: In the present work, Hg (II) is considered as one of the most dangerous elements being released excessively into the environment from various sources. Therefore, the aim of this study is the removal of Hg (II) from wastewater effluent by synthesizing a magnetic chitosan modified with glutaraldehyde (MCS-GA) as an adsorbent. The composite structure was characterized using SEM/EDAX, FTIR, and XRD techniques. The adsorbent was tested by a batch system to determine the optimum conditions for removing Hg (II) under real conditions. RESULTS: The results showed that 0.5% GA effectively enhanced the removal efficiency. The maximum adsorption capacity of MCS-GA was 96 mg g −1 at pH 5.0 and 25 ∘ C. The adsorption isotherm data obeyed the Langmuir model (R 2 >0.981) and pseudo-second-order (R 2 >0.996) kinetic models. It was also found that Hg (II) adsorption on MCS-GA is inherently exothermic and occurs spontaneously. The reusability of MCS-GA was approved over 12 sequential cycles of adsorption-desorption. ANOVA analysis showed that the contact time has a synergistic effect on Hg (II) removal, whereas pH and initial concentration have antagonistic effects. CONCLUSION: Overall, the synthesized adsorbent was able to remove Hg (II) efficiently under both experimental and real conditions.

Characterization of Magnetic Nanoparticles Coated with Chitosan: A Potential Approach for Enzyme Immobilization

“…A limited number of studies have employed RSM approaches to optimize the generation of magnetic nanoparticles for enzyme immobilization. RSM keeps the number of experiments to a minimum for a relatively large number of significant factors as compared to those involving the simple, time consuming "one factor at a time" design [18].…”

Using composite chitosan-graphene oxide to eliminate reactive blue 19 from water solutions: the study of adsorption kinetics and reaction thermodynamics

“…In these equations, R is the percentage of eliminated dye, C 0 is the initial dye concentration (mg/l), C e is the concentration of the remaining dye in the solution (mg/l), q t is the amount of adsorbed dye during time (mg/g), q e is the amount of adsorbed dye in the equilibrium status (mg/g), V is the solution volume (l), and M is the adsorbent dose (g). The present study focused on the impact of the initial dye concentration (20,40,50, and 60 mg/l), pH (4,7,9), adsorbent dose (0.1, 0.3, 0.5, 0.7, 1, and 1.5 g/l), and exposure time (10,20,30,40,60,90, and 120 min) were examined [9,15,21]. To come up with the optimal condition, the impacts of adsorbent dosage (0.1, 0.3, 0.5, 0.7, and 1 g/l), pH (2, 7, and 9), concentration (20,40,50, and 60 mg/l), and exposure time (10,20,30,40,60,90, and 120 min) were measured.…”

“…In their study, Justin et al attributed the frequencies of 2θ = 11 and 2θ = 20 to chitosan [28]. Also, Kumar et al [21] indicated that the frequency of 2θ = 21.18 has to do with chitosan graphene oxide.…”

Removal of Hg(ii) in aqueous solutions through physical and chemical adsorption principles

“…Some macromolecules can form well-organized organic functional group chains by self-assembly ways and these are combined with other active matters to make synergetic effects of adsorption. [57][58][59][60] Asif et al synthesized a nuclearshell hybrid material containing iron nanoparticles coated with chitosan and calixarene composite. 61 The organic calixarene macromolecules possess adsorptive activity.…”