Synthesis and Characterization of Green ZnO@polynaniline/Bentonite Tripartite Structure (G.Zn@PN/BE) as Adsorbent for As (V) Ions: Integration, Steric, and Energetic Properties

Abstract

A green ZnO@polynaniline/bentonite composite (G.Zn@PN/BE) was synthesized as an enhanced adsorbent for As (V) ions. Its adsorption properties were assessed in comparison with the integrated components of bentonite (BE) and polyaniline/bentonite (PN/BE) composites. The G.Zn@PN/BE composite achieved an As (V) retention capacity (213 mg/g) higher than BE (72.7 mg/g) and PN/BE (119.8 mg/g). The enhanced capacity of G.Zn@PN/BE was studied using classic (Langmuir) and advanced equilibrium (monolayer model of one energy) models. Considering the steric properties, the structure of G.Zn@PN/BE demonstrated a higher density of active sites (Nm = 109.8 (20 °C), 108.9 (30 °C), and 67.8 mg/g (40 °C)) than BE and PN/BE. This declared the effect of the integration process in inducing the retention capacity by increasing the quantities of the active sites. The number of adsorbed As (V) ions per site (1.76 up to 2.13) signifies the retention of two or three ions per site by a multi-ionic mechanism. The adsorption energies (from −3.07 to −3.26 kJ/mol) suggested physical retention mechanisms (hydrogen bonding and dipole bonding forces). The adsorption energy, internal energy, and free enthalpy reflected the exothermic, feasible, and spontaneous nature of the retention process. The structure is of significant As (V) uptake capacity in the existence of competitive anions or metal ions.

Insight into the synergetic, steric and energetic properties of zeolitization and cellulose fiber functionalization of diatomite during the adsorption of Cd(ii): advanced equilibrium studies

“…1,2 Uncontrolled, extensive, and continuous discharging of polluted effluents that are related to mining, agricultural, and industrial activities represent the main sources and reasons for the water pollution problem and its related environmental phenomena. 3,4 Such discharged effluents are highly saturated with several species of dissolved organic chemical compounds, whether organic (pharmaceutical residuals, petrochemicals, pesticides, and dyes) or inorganic (heavy metals, phosphate, ammonium, sulfate, and nitrate), and most of them, at their abnormal concentrations, display notable adverse environmental and health impacts. 5,6 The extensive existence of heavy metals as dissolved ions or chemical complexes with other chemicals in water resources represents one of the critical hazardous challenges that threaten the safety of our ecosystem and the health of humanity.…”

Insight into the Effect of Sulfonation Techniques on the Adsorption Properties of −SO3H Surface-Functionalized Coal as Adsorbent for Malachite Green Dye: Steric and Energetic Investigation

“…The Gaussian energies of the N.C, MS.C, and SS.C adsorption systems for MG dye were recognized as parameters for the addressed D-R isotherm model (Table ). The obtained energies for N.C (3.02 to 3.6 kJ/mol), MS.C (2.55 to 2.73 kJ/mol), and SS.C (2.7 to 3.01 kJ/mol) authorize dominant effect for the physisorption mechanisms (<8 kJ/mol) during their adsorption reactions for MG molecules …”

“…The obtained energies for N.C (3.02 to 3.6 kJ/mol), MS.C (2.55 to 2.73 kJ/mol), and SS.C (2.7 to 3.01 kJ/mol) authorize dominant effect for the physisorption mechanisms (<8 kJ/mol) during their adsorption reactions for MG molecules. 45 …”

Characterization of cellulose-functionalized phillipsite biocomposite as an enhanced carrier of oxaliplatin drug during the treatment of colorectal cancer: loading, release, and cytotoxicity

“…The loading equilibration states of N.Ph and CF/N.Ph was identied aer the complete occupation of all the existing sites with the encapsulated OXPN molecules. 38 3.2.1.3. OXPN concentration.…”