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

Siti Fairos Ab Shattar,Nor Azazi Zakaria,Keng Yuen Foo

doi:10.1038/s41598-020-76723-w

Siti Fairos Ab Shattar, Nor Azazi Zakaria + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-76723-w

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Journal: Scientific Reports	Publication Date: Nov 19, 2020
Citations: 12	License type: open-access

Affiliation: Universiti Sains Malaysia

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.

Highlights

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 specific action of ametryn on plants is the inhibition of photosynthesis process, at the photosystem II (PSII), leading to the blockage of electron transport by displacing plastoquinone from the unique binding sites on the protein sub-unit, resulting in chlorosis and tissue n ecrosis[1]
Considerable studies have demonstrated that these pesticides could be up taken by the plant roots, and accumulate in the apical meristems to generate mutagenic and carcinogenic damages to the enzymatic systems and deoxyribonucleic acid (DNA)

Summary

Introduction

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. Bentonite activation is a complex phenomenon that involves the substitution of exchangeable cations, A l3+, Mg2+, and Fe2+ against protons from the octahedral sheet, resulting in the improvement of bleaching effectiveness, greater hydrophobicity and porosity structure, strongly protonated clay mineral surface, increase in specific surface area from the original 20–130 m 2/g to higher than 200 m 2/g, and generate higher affinity to the organic molecules such as ametryn and m etolachlor[13] In this sense, the present work was carried out to shed light on the feasibility of acid modified bentonite (AB) for the adsorptive treatment of ionic ametryn and non-ionic metolachlor, the second generation of industrial pesticide contaminants from the aqueous solution. The adsorption isotherms, kinetics and thermodynamics analysis were elucidated

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Results

Conclusion