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(searched for: doi:10.33945/sami/ecc.2020.7.6)
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Nida Shams Jalbani, , Shahabuddin Memon, , Asif Ali Bhatti
Journal of Dispersion Science and Technology pp 1-9; https://doi.org/10.1080/01932691.2022.2046043

Abstract:
Calixarenes are known as fascinated macromolecules due to their flexible structure that can be cast into different fields of application. These macromolecules have been used as quick and highly selective functional material for the extraction and separation of metal ions. This study explores metal ion removal efficiency of new calixarene coated silica resin from aqueous environment through solid phase extraction. The calixarene-coated silica resin (CCS resin) was synthesized and characterized by FTIR, SEM, XRD, EDS and BET. Static and dynamic adsorption experiments were followed to check the removal efficiency of CCS resin. Adsorption experiment shows that, CCS resin has strong potential for the removal of divalent and trivalent metal ions as compare to monovalent metal ions. Adsorption data have been evaluated by applying Langmuir, Freundlich, D-R models and Thomas dynamic adsorption models. The adsorption isotherm of the CCS resin agreed well with the Langmuir adsorption equation with regression coefficient of 0.99 and good monolayer adsorption capacities such as 3.22, 2.95, 3.04, 3.11, 2.81 and 2.82 (mol.g−1) for Hg2+ Pb2+ La3+ Cr3+ Al3+ and Fe3+ respectively. The D-R isotherm model suggests that the adsorption process follow ion exchange mechanism with mean sorption energy falls in the range of 9.0–16 KJ.mol−1. Moreover, the exhaustion capacity of column was calculated by using the Thomas model, which shows very small qo value with good fit to data (R2 =0.99). The thermodynamic and kinetic studies have also been performed, which reveals that the reaction is spontaneous and exothermic in nature and follows pseudo second-order kinetics. Graphical Abstract
Samiha Gul, Fakhar N. Memon,
New Journal of Chemistry, Volume 46, pp 3448-3463; https://doi.org/10.1039/d1nj05669g

Abstract:
The present study is devoted to the application of Central Composite Design (CCD) to purify water contaminated with toxic metal ions (Pb2+, Cd2+ and Hg2+) using a p-tert-diethanolaminomethylcalix[4]arene (DEA-C4) based silica resin. The synthesized material was characterized using SEM, FTIR and EDX techniques. Three effective parameters (pH, adsorbent dosage and concentration of metal ion) were optimized by assessment with CCD. The data was analyzed using the quadratic model and the obtained results revealed the highest % adsorptions for Pb2+ (92.7), Cd2+ (93.7) and Hg2+ (88.2) at the optimum points for pH (5.4, 3.18 and 3.89), adsorbent dosage (23.8, 25.5 and 26.12 mg) and metal ion concentration (5.3, 7.62 and 7.18 ppm), respectively. Analysis of variance (ANOVA) results show a good fit for the regression model, showing R2 values of 0.99 for Pb2+, 0.99 for Cd2+ and 0.98 for Hg2+. Furthermore, the results from Freundlich adsorption isotherms suggest its favorability, as the values for n are >1 (i.e., 7.06, 8.85 and 13.2) and there are higher values for R2 = 0.97, 0.99 and 0.98 for Pb2+, Cd2+ and Hg2+, respectively. However, for the Langmuir isotherm, the value of the separation factor RL is >1 (1.01, 1.02 and 1.05 for Pb2+, Cd2+ and Hg2+, respectively), revealing its un-favorability. In kinetics, the pseudo-second-order kinetic model (Ho and McKay) shows R2 values of 0.998, 0.999 and 0.999 for Pb2+, Cd2+ and Hg2+, suggesting the chemical reaction seems significant in the rate controlling step. The thermodynamic results concluded that the reaction is spontaneous and exothermic in nature.
, Nida Shams Jalbani, Savas Kaya, Goncagül Serdaroglu, Mustafa Elik, Shahabuddin Memon
Separation Science and Technology, Volume 57, pp 1884-1899; https://doi.org/10.1080/01496395.2021.2009869

Abstract:
Water is being contaminated by different oxyanions which have many negative effects on the human body. This study deals with the adsorptive removal of Cr2O7−2, AsO4−3, and ClO4−1 oxyanions from water using diethanolaminomethylcalix[4]arene bonded silica (DBS) resin. The capacity of DBS resin for the removal of oxyanions was checked through batch method under the optimized parameters such as pH, adsorbent dosage, concentration of oxyanions, and effect of temperature. The experimental data were analyzed through Langmuir, Freundlich, and Dubinin–Radushkevitch (D–R) adsorption isotherm models and the Langmuir model was the best fit model with a good correlation coefficient (R2 0.998). The thermodynamic and kinetic studies were performed to check the mechanism and adsorption pathway of oxyanions onto DBS resin. The thermodynamic parameters such as (Δ, Δ, and Δ) describes that the adsorption of oxyanions was spontaneous and endothermic and followed by pseudo second order kinetic models very well. The reusability of resin was also checked and it has been observed that after 27 cycles only 2% loss in adsorption capacity. Moreover, the oxyanions were optimized at the B3LYP/LANL2DZ/6-311++G (d,p) level using G09W software to analyze the oxyanions-DBS interactions phenomenon. Graphical abstract
Yong-Yuan Chen, Xi-Wen Lan, Hao Ren, Wen-Jie Li, Jun Chen, Xin-Yu Jiang,
Journal of Environmental Chemical Engineering, Volume 9; https://doi.org/10.1016/j.jece.2021.106500

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, Nida Shams Jalbani, Savas Kaya, , Riadh Marzouki, Shahabuddin Memon
International Journal of Environmental Analytical Chemistry pp 1-17; https://doi.org/10.1080/03067319.2021.1979534

Abstract:
This study describes the removal of methyl orange (MO) and methyl red (MR) dyes from water samples using morpholinomethylcalix[4]arene immobilised silica (MIS) resin. The silica surface has been modified by p-morpholinomethylcalix[4]arene moiety and was characterised by FT-IR spectroscopy and SEM techniques. The adsorption capacity of MIS-resin was checked through batch adsorption experiments under the optimised conditions of pH, MIS-resin dose, time, and temperature. Results show that adsorption of MO and MR dyes are highly affected by the change in pH; thus, the higher adsorption percentages were achieved at pH 5.3 and 6.6 respectively. The adsorbent dosage has been optimised and it was noticed that the maximum adsorption was achieved by using 40 mg.L−1 of MIS-resin dose. The adsorption rate of dyes was investigated by applying the pseudo-first and second-order kinetic models and it has been observed that the experimental data shows a better correlation coefficient with the pseudo-second-order kinetic model. The feasibility of adsorption was analysed by thermodynamic parameters such as ∆H°, ∆G°, and ∆S° values indicate that the adsorption of dyes is exothermic and spontaneous. The equilibrium data have been validated using Langmuir and Freundlich models and the Langmuir model has a good correlation coefficient (R2 0.99). The MIS-resin was applied onto industrial effluents and it has been observed that the prepared resin is a very efficient adsorbent for the treatment of dyes contaminated wastewater. The adsorption of MO and MR dyes onto MIS-resin was well defined by computational chemical modelling at the B3LYP/LANL2DZ/6-311++G (d,p) level using G09W software.
Mohammed M. Al-Mahadeen, Anwar G. Jiries, Salah A. Al-Trawneh, , Ahmad S. Eldouhaibi,
Published: 16 September 2021
Chemical Physics Letters, Volume 783; https://doi.org/10.1016/j.cplett.2021.139053

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Nida Shams Jalbani, , Shahabuddin Memon, Ranjhan Junejo, Asif Ali Bhatti, Mehmet Lütfi Yola, Muhammad Tawalbeh,
Published: 17 June 2021
Journal of Molecular Liquids, Volume 339; https://doi.org/10.1016/j.molliq.2021.116741

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, Hassan Ouachtak, Hassan Alhajri, , Ghassab Al-Mazaideh, ,
Separation Science and Technology, Volume 57, pp 542-554; https://doi.org/10.1080/01496395.2021.1931326

Abstract:
Chemical modification of chitosanwas successfully carried out using 2,3-dihydroxy-benzaldehyde by a chemical condensation reaction. Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area,Thermal gravimetric analysis (TGA), and X-Ray Diffraction methods were performed for characterization of the chitosan-derived Schiff base adsorbent material. The prepared adsorbent’s efficiency in removing Rhodamine B dye from aqueous solution was explored, and experimental data were analyzed using isothermal and kinetic models. The BET surface area of chemically modified chitosan was greatly enhanced 125.8 m2g−1 with mesoporous characteristics. The maximum uptake was recorded at pH 8, while the maximum removal capacity was 233.4 mg g−1(25°C). The kinetic data were better fitted using nonlinear pseudo-first-order.
, Nida Shams Jalbani, Savas Kaya, Goncagül Serdaroglu, , Shahabuddin Memon
Separation Science and Technology, Volume 57, pp 339-353; https://doi.org/10.1080/01496395.2021.1900252

Abstract:
The current research demonstrates the adsorptive removal of RY-18, RR-2, RB-13, and RB-171 dyes from wastewater samples using p-diethylaminomethylcalix[4]arene silica appended (DSA) resin. The DSA resin shows high adsorption capacity for reactive dyes during the batch adsorption experiments under the optimized parameters such as DSA resin dosage, pH, and temperature. The adsorption equilibrium results were defined by Irving-Langmuir and Freundlich-isotherm models and it was found that the Freundlich model is the best fit with good multilayer adsorption capacity along with good correlation coefficient value (R2 0.9991) for reactive dyes, while the energy calculated by D-R model describes the adsorption mechanism that is physisorption in nature. Moreover, a thermodynamic study was also performed, which shows that the adsorption of reactive dyes is endothermic and spontaneous in nature. From the kinetic study, it has been revealed that the adsorption takes place by following a pseudo-second-order kinetic model. Besides this, the adsorption phenomenon is explained by density functional theory DFT calculations. The DSA resin was applied onto industrial wastewater samples and it has been observed that above 98% reactive dyes were adsorbed successfully. After washing for regeneration, the DSA resin has above 98% adsorption capacity, which proves that the DSA is a regenerable adsorbent. Graphical representation of dyes adsorption onto DSA resin
, Nida Shams Jalbani, Shahabuddin Memon, Savas Kaya, Sultan Erkan, Goncagül Serdaroǧlu, Ismail Murat Palabiyik
Journal of Chemical & Engineering Data, Volume 66, pp 379-388; https://doi.org/10.1021/acs.jced.0c00735

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