Removal of herbicide paraquat from aqueous solutions by bentonite modified with mesoporous silica

Removal of herbicide paraquat from aqueous solutions by bentonite modified with mesoporous silica

In this study, a comparative experiment was performed regarding the removal of herbicide paraquat (PQ2+) from an aqueous solution using bentonite (BNT) modified by silica (BNTS). The obtained composites as adsorbent were characterized using FESEM, EDS-mapping, FTIR and BET analyses. The adsorption k...

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Bibliographic Details
Published in:Materials chemistry and physics Vol. 262; p. 124296
Main Authors: Rasaie, Ailin, Sabzehmeidani, Mohammad Mehdi, Ghaedi, Mehrorang, Ghane-Jahromi, Mojtaba, Sedaratian-Jahromi, Amin
Format: Journal Article
Language:English
Published: Lausanne Elsevier B.V 01-04-2021
Elsevier BV
Subjects:
Adsorbents
Adsorption
Aqueous solutions
Bentonite
Clay
Herbicide
Herbicides
Isotherms
Paraquat
Response surface methodology
Silicon dioxide
Van't hoff equation
Clay
Response surface methodology
Adsorption
Herbicide
Van't hoff equation
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Summary:In this study, a comparative experiment was performed regarding the removal of herbicide paraquat (PQ2+) from an aqueous solution using bentonite (BNT) modified by silica (BNTS). The obtained composites as adsorbent were characterized using FESEM, EDS-mapping, FTIR and BET analyses. The adsorption kinetic of PQ2+ was relatively fast and the equilibrium was achieved within 2 min due to the absence of internal diffusion resistance. The efficiency of PQ2+ adsorption on BNTS composite was investigated based on the various factors such as initial PQ2+ concentration, adsorbent mass and the solution pH according to the central composite design (CCD). The Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models were used to discuss the adsorption behavior. The equilibrium experimental data could be well presented by the Langmuir isotherm and the maximum adsorption capacity for activated BNT and BNTS reached 5.93 and 11.75 mg g−1. Based on linear and nonlinear form of the thermodynamic equation, the results illustrated that the herbicide PQ2+ adsorption onto as-synthesized BNTS composite was an exothermic and a spontaneous process. •Bentonite clay modified silica composite was prepared and used as the adsorbent.•Efficiency of bentonite modified silica for removal of herbicide paraquat was investigated.•The influence of various factors on removal paraquat were investigated.•The adsorption fitted well with the Langmuir isotherm model, and the process was exothermic.•Effect of ionic strength on paraquat adsorption was conducted.
ISSN:0254-0584
1879-3312
DOI:10.1016/j.matchemphys.2021.124296