Preparation and use of maize tassels’ activated carbon for the adsorption of phenolic compounds in environmental waste water samples

The determination and remediation of three phenolic compounds bisphenol A (BPA), ortho-nitrophenol (o-NTP), parachlorophenol (PCP) in wastewater is reported. The analysis of these molecules in wastewater was done using gas chromatography (GC) × GC time-of-flight mass spectrometry while activated carbon derived from maize tassel was used as an adsorbent. During the experimental procedures, the effect of various parameters such as initial concentration, pH of sample solution, eluent volume, and sample volume on the removal efficiency with respect to the three phenolic compounds was studied. The results showed that maize tassel produced activated carbon (MTAC) cartridge packed solid-phase extraction (SPE) system was able to remove the phenolic compounds effectively (90.84–98.49 %, 80.75–97.11 %, and 78.27–97.08 % for BPA, o-NTP, and PCP, respectively) . The MTAC cartridge packed SPE sorbent performance was compared to commercially produced C18 SPE cartridges and found to be comparable. All the parameters investigated were found to have a notable influence on the adsorption efficiency of the phenolic compounds from wastewaters at different magnitudes

Removal of 2,4-dichlorophenol using cyclodextrin-ionic liquid polymer as a macroporous material: characterization, adsorption isotherm, kinetic study, thermodynamics

Cyclodextrin-ionic liquid polymer (βCD-BIMOTs-TDI) was firstly synthesized using functionalized β-Cyclodextrin (CD) with 1-benzylimidazole (BIM) to form monofunctionalized CD (βCD-BIMOTs) and was further polymerized using toluene diisocyanate (TDI) linker to form insoluble βCD-BIMOTs-TDI. SEM characterization result shows that βCD-BIMOTs-TDI exhibits macropore size while the BET result shows low surface area (1.254m2g-1). The unique properties of the ILs allow us to produce materials with different morphologies. The adsorption isotherm and kinetics of 2,4-dichlorophenol (2,4-DCP) onto βCD-BIMOTs-TDI is studied. Freundlich isotherm and pseudo-second order kinetics are found to be the best to represent the data for 2,4-DCP adsorption on the βCD-BIMOTs-TDI. The presence of macropores decreases the mass transfer resistance and increases the adsorption process by reducing the diffusion distance. The change in entropy (ΔS°) and heat of adsorption (ΔH°) for 2,4-DCP on βCD-BIMOTs-TDI were estimated as -55.99J/Kmol and -18.10J/mol, respectively. The negative value of Gibbs free energy (ΔG°) indicates that the adsorption process is thermodynamically feasible, spontaneous and chemically controlled. Finally, the interactions between the cavity of βCD-BIMOTs and 2,4-DCP are investigated and the results shows that the inclusion of the complex formation and π-π interaction are the main processes involved in the adsorption process

Cyclodextrin modified ionic liquid material as a modifier for cloud point extraction of phenolic compounds using spectrophotometry

A greener method based on cloud point extraction (CPE) in the presence of b-cyclodextrin (CPE-bCD) and β-cyclodextrin functionalized with ionic liquids (CPE- β CD-IL) systems were investigated and compared for the removal of 2,4,6-TCP and 4-NP in aqueous sample using UV-Vis spectrophotometric method. In the present study, β CD-IL modifier, was used in CPE- β CD-IL system as an enhancement in the removal of 2,4,6-TCP and 4-NP. The removal of 2,4,6-TCP and 4-NP were optimum at pH 7 with concentration of DC193C, 0.5 (v/v %), for this work. Apart from that, the removal process was found to be optimum at 10 mg L-1 of both modifies concentration. For the isotherm study, monolayer solubilization capacity is greater for 2,4,6-TCP than 4-NP. The performance of the β CD-IL modifier towards the hydrophilic 4-NP showed enhanced extraction efficiency in the present study as compared to the β -CD modifier. Finally, the interactions between the cavity of β CD-IL with 4-NP and DC193C were investigated and the results show that the inclusion of the complex formation, hydrogen bonding between DC193C and 4-NP, π- π interaction, electrostatic attraction between the imidazolium ring of the β CD-IL was the main interactions involved in the extraction process

Supramolecular interaction of 2,4-dichlorophenol and beta-cyclodextrin functionalized ionic liquid and its preliminary study in sensor application

The supramolecular interaction of 2,4-dichlorophenol (2,4-DCP) and beta-cyclodextrin fiinctionalized ionic liquid, a mono-6-deoxy-6-(3-benzylimidazolium)-beta-cyclodextrintosylate (beta-CD-BIMOTs) has been investigated. The inclusion complex of beta-CD-BIMOTs-2,4-DCP complex was analyzed with conventional spectroscopic techniques and compared with native beta-CD-2,4-DCP complex. The mechanism of the inclusion too was studied and discussed based on FTIR, H-1 NMR and 2D NOESY analysis. beta-CD-BIMOTs has a stronger binding affinity towards 2,4-DCP compared to native beta-CD based on the formation constant value calculated. In this work, modified electrodes were fabricated by mixing beta-CD-BIMOTs and carbon paste electrode (CPE) for determination of 2,4-DCP. The electrochemical behavior of 2,4-DCP at beta CD-BIMOT5/CPE exhibits higher electrochemical performance than that of native beta-CD/CPE and CPE, revealing that CPE modified beta-CD-BIMOTs not only displays good electrical properties of the ionic liquid but also exhibits high supramolecular recognition properties of beta-CD-BIMOTs through the formation of an inclusion complex between beta-CD-BIMOTs and 2,4-DCP molecules. This preliminarily study shows that beta-CD-BIMOTs can act as an inexpensive electrochemical sensor that is suitable for the determination of 2,4-DCP. (C) 2015 Elsevier B.V. All rights reserved

Exploring the performance of magnetic methacrylic acid-functionalized β-cyclodextrin adsorbent toward selected phenolic compounds

Abstract In this study, the removal of bisphenol A (BPA), 2,4-dinitrophenol (2,4-DNP), and 2,4-dichlorophenol (2,4-DCP) using a new magnetic adsorbent methacrylic acid-functionalized β-cyclodextrin (Fe3O4@MAA-βCD) was evaluated. The materials were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscopy, and X-ray diffraction. The batch adsorption experiments optimized and evaluated various operational parameters such as pH, contact time, sorbent dosage, initial concentration, and temperature. The result shows that DNP possessed the most excellent affinity toward Fe3O4@MAA-βCD adsorbents compared to BPA and DCP. Also, BPA showed the lowest removal and was used as a model analyte for further study. The adsorption kinetic data revealed that the uptake of these compounds follows the pseudo-second order. Freundlich and Halsey isotherms best-fitted the adsorption equilibrium data. The desorption process was exothermic and spontaneous, and a lower temperature favored the adsorption. Furthermore, hydrogen bonding, inclusion complexion, and π–π interactions contributed to the selected phenolic compound’s adsorption