Application of ZnO nanorods as an adsorbent material for the removal of As(III) from aqueous solution: kinetics, isotherms and thermodynamic studies

Abstract

Removal of metals from wastewaters causes a big concern from the environmental point of view due to their extreme toxicity towards aquatic life and humans. Application of As(III) from aqueous solution by ZnO nanorods as adsorbent has been investigated in the present study. The synthesized nanorods were characterized by XRD, FT-IR spectroscopy, SEM, and thermogravimetric analysis. Optimum biosorption conditions were determined with respect to pH, adsorbent dose, contact time, and temperature. The experimental data were examined using the Lagergren's first-order, pseudo-second-order and intraparticle diffusion kinetic models. The results revealed that the pseudo-second-order kinetic model provided the best description of the data. Langmuir and Freundlich isotherm models were applied to the equilibrium data. The maximum As(III) sorption capacity of ZnO nanorods was found to be 52.63 mg/g at pH 7, adsorbent dose 0.4 g, contact time 105 min, and temperature 323 K. The calculated thermodynamic parameters, ΔG o (between − 5.741, − 5.342 and − 4.538 kJ/mol at 303-323 K), ∆H o (13.75 kJ/mol) and ∆S o (0.0616 J/mol K) showed that the sorption of As(III) onto ZnO nanorods was feasible, spontaneous and exothermic, respectively.

One-Pot Synthesis of Zinc Oxide Nanoparticle for Bromophenol Blue Adsorption and Its Antifungal Activity Against Filamentous Fungi

“…3e). This result is consistent with other studies depicting the endothermic adsorption of As(III) 28 , azo dyes 29 and, Pb(II) ions 71 on ZnONPs. It is important to mention that ∆H o values in the range of 2.1 -20.9 kJ/mol and 80 -200 kJ/mol are attributed to physisorption and chemisorption respectively 84 .…”

Experimental Investigation of Thermodynamics, Kinetics, and Equilibrium of Nickel Ion Removal from Wastewater Using Zinc Oxide Nanoparticles as the Adsorbent

“…The move of the peak from 1078.21 to 1080.14 cm −1 suggests the contribution of the C-O set in limited Ni (II).These results are in agreement with a pervious reported study [27]. c) Surface morphology test SEM measurement of the able to adsorb substances is the most significant estimation since the adsorption limit principally relies upon structure and porosity for the surface [20,27].…”

“…Also, a wide absorption band around 428-570 cm −1 is referred to the mineral zinc-oxide extension group. The results of FT-IR spectra for zinc oxide nanoparticles are in a good agreement with study [20]. Figure 2b depicts the FT-IR spectra after Ni(II) filled, the wide peak at 3429.43 cm −1 which is related to O-H stretching that present in alcohol and climbs during adsorption method.…”

“…ΔHº -T.ΔSº (10) It is possible to determine , ΔHº and ΔSº using the slope and intercept of Van't Hoff scheme of ln K C versus (1/T) through Eq.11 [20]:…”

Application of ZnO Nano Rods for the Batch Adsorption of Cr(VI): A Study of Kinetics and Isotherms

“…In addition to these, certain nano ZnO doped with other metals have also been reported as adsorbents (Ghiloufi et al, 2016;Meng et al, 2015). Similarly, investigations involving ZnO nano rods were also carried out for the removal of toxic metals (Ghaedi et al, 2015;Yuvaraja et al, 2018). But, however, study related to ZnO with similar morphology as in the present study for chromium adsorption is found to be scarce in literature.…”