One step acid activation of bentonite derived adsorbent for the effective remediation of the new generation of industrial pesticides

Abstract

Herein, the facile one step acid activation of bentonite derived functionalized adsorbent (AB) for the effective remediation of both ionic and non-ionic secondary pesticides, ametryn and metolachlor has been attempted. The surface characteristics of AB were examined by the nitrogen adsorption–desorption analysis, scanning electron microscopy (SEM), and Fourier Transforms Infrared (FTIR) Spectroscopy. The adsorptive behavior was evaluated with respect to the effect of contact time, initial concentrations and solution pH. The equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherm models, while the adsorption kinetic was analyzed using the pseudo-first order and pseudo-second order kinetic equations. Thermodynamic parameters including the standard enthalpy change (ΔH°), standard entropy change (ΔS°), and Gibbs free energy change (ΔG°) were established. Thermodynamic analysis illustrated that the adsorption process was feasible and exothermic in nature, while the characterization findings verified the alteration of FTIR bands, and a high specific surface area of 464.92 m2/g, with a series of pores distributed over the surface. Equilibrium data was best confronted to the pseudo-second order kinetic model, while the adsorptive removal of ametryn and metolachlor onto AB was satisfactory described by the Langmuir isotherm model, with the monolayer adsorption capacities for ametryn and metolachlor of 2.032 and 0.208 mmole/g respectively. The findings outlined the potential of the newly develop AB for the on-site treatment of pesticide polluted water.

Sodium salt-assisted low temperature activation of bentonite for the adsorptive removal of methylene blue

“…These Al, Mg and Fe hydroxides that could be adsorbed by the broken edge sites, or present concurrently may appear as the interlayer or coating surface between the clay minerals. The reactivity of this phase is significantly higher than the free hydroxides, contributed by the three major surface binding sites, notably permanent charged siloxane surface, mono-coordinated and newly formed hydroxide species within the clay edges 11 . With the aforementioned, in this work, the sodium salt-assisted low temperature activation of highly porous bentonite derived adsorbent (BB) was carried out by varying the modification ratio.…”

Statistical Analysis of Phenol Removal Using Modified Iraqi Bentonite from Wastewater by Adsorption Process

“…Adsorption characteristics that impacted the adsorption process were studied using a UV-Vis spectrophotometer. The initial phenol concentration was changed (50, 100,125, 150 mg L-1), pH (3,6,9,12), and temperature range (25,35,45, and 55°C ) To study the effect of variables on adsorption. The Minitab software's design of the experiments option's upper and lower range was used to calculate the total number of experiments.…”

One-step synthesis of super-absorbent nanocomposite hydrogel based on bentonite

“…However, the as-synthesized NB has a lower surface are (11.08 m 2 .g −1 ) than the the raw bentonite (24.08 m 2 .g −1 ). By activation bentonite with 8.0 M HNO 3 at 60 °C for 24 h, KengYuen Foo has produced NB with pesticide adsorption capacity of 2.032 mmol.g −1 [11]. The NB with a high surface area (493.97-868 m 2 .g −1 ) was also synthesized using a denaturation method with strong acids (e.g.…”

“…The NB exhibited high adsorption capacity for Pb 2+ , Cu 2+ , and Co 2+ ions in aqueous solution [12]. The benefits of acidification include simple filtration, enhanced material's surface qualities, removal of undesired components, and development of acidic adsorption sites that promote adsorption capacity, as compared to the raw bentonite [11]. However, the use of acidification method requires time-consuming synthesis and high concentrations, which cause negative impacts to the environment.…”