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Your search keyword '"Nilesh V. Rathod"' showing total 7 results
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7 results on '"Nilesh V. Rathod"'

1. Efficient removal of toxic Cd(II) ions from waste streams by a novel modified biodegradable magnetic sorbent

Author

Jayshri S. Jadhao, Nilesh V. Rathod, Ankita Rao, Chandrakant D. Ghugare, Santosh M. Chavan, Akash V. Kubade, Vrashali S. Kalyani, and Arun B. Patil

Subjects
Orange peel, Chitosan and Fe3O4 composites, Cd(II) adsorption, Reusability, Application, Inorganic chemistry, QD146-197
Abstract

Environmental remediation is challenged by the removal of harmful heavy metal contaminants from industrial waste streams. Because of its low cost and great effectiveness, adsorption is a commonly used separation method, particularly in environmental cleanup. Inexpensive, biodegradable orange peel-chitosan and Fe3O4 magnetic particles (Fe3O4-OP-CS) were combined in a simple process to create an innovative composite. Their structure and morphology were studied using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analyses. At room temperature, adsorption experiments were conducted, and variables such pH, initial metal ion concentration, and contact time were tuned to maximize Cd(II) removal. The results of harmful Cd(II) sorption using the synthesized composite showed that its adsorption kinetics and sorption isotherm confirm to the pseudo-second-order and Langmuir models, respectively. The thermodynamic analysis showed that Cd(II) adsorption is exothermic and spontaneous. In comparison to previously reported materials, the new composite also displayed a high adsorption capacity (qmax) of 251.88 mg/g. The composite showed three cycles of reuse and might still be able to promise a maximum saturated adsorption capacity of more than 92%, and tolerance to related metal ions (Mn, Fe, Pb, and Cr) present in Cd (II). In addition to Cd(II) sorption for preconcentration and remediation before Cd testing from waste, digested tobacco, and battery samples, the proposed method is also credible for Cd(II) sorption.

Published
2023
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3. The investigation of cooperative binding between p-sulfonatocalix[6]arene and fluorescein with transition metal ions by spectrometrically

Author

G.N. Chaudhari, Dipalee D. Malkhede, V.S. Sapkal, Vrashali S. Kalyani, Sharadchandra Gawhale, Nilesh V. Rathod, Rupali G. Thorave, Rajesh Sapkal, and Sanhita V. Patil

Subjects
010405 organic chemistry, Hydrogen bond, Chemistry, Cooperative binding, General Chemistry, 010402 general chemistry, Kinetic energy, Electrostatics, 01 natural sciences, 0104 chemical sciences, Crystallography, chemistry.chemical_compound, Molecule, Binary system, Fluorescein, Ternary operation
Abstract

The ternary complexes are formed by self-assembly through cooperative hydrogen bonding between p-SCX6-FL and M2+ through water molecule which is reinforced by columbic and electrostatic interactions. The binding efficiency of Cu2+ and Zn2+ is observed at a greater extent than Co2+ and Ni2+. Furthermore, the kinetic study of p-SCX6-FL-Cu2+ and Zn2+ reveals that the process of complexation is slower than the binary system (FL+p-SCX6). Synopsis. Herein we report the systematic complexation study of ternary model i.e., p-SCX6-FL-M2+ by IR, NMR and UV-Visible and florescence technique.

Published
2019

4. Investigation of host-guest complexation of the ternary model: p-Sulfonatothiacalix[4]arene-fluorescein-M2+

Author

Dipalee D. Malkhede, Vrashali S. Kalyani, S.T. Gawhale, R.S. Sapkal, V.S. Sapkal, Prabhat K. Singh, G.N. Chaudhari, and Nilesh V. Rathod

Subjects
010405 organic chemistry, Chemistry, Infrared spectroscopy, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Transition metal ions, 0104 chemical sciences, Ion, Inorganic Chemistry, chemistry.chemical_compound, Materials Chemistry, Proton NMR, Physical and Theoretical Chemistry, Fluorescein, Cooperative interaction, Ternary operation, Two-dimensional nuclear magnetic resonance spectroscopy
Abstract

In comparison to traditional calyx[4]arene, thiacalix[4]arene is unique due to its bridging S-atoms. Therefore, functionalized p-sulfonato thiacalix[4]arene has been used for the detection of some transition metal ions. The inclusion behavior between the important water soluble p-sulfonato thiacalix[4]arene with fluorescein and M2+ (Co2+, Ni2+, Cu2+, Zn2+) ions has been studied using a spectrofluorometric method. 1H NMR, 2D NMR and IR spectra also supported the complexation. The complex stability follows the order Cu2+ > Zn2+ > Co2+ > Ni2+, which is supported by the Irving-Williams series. The combined results demonstrate the cooperative interaction of the M2+ ions with p-sulfonato thiacalix[4]arene and this is further supported by a molecular docking study.

Published
2020

5. Studies on Complexation and Supercritical Fluid Extraction of Cd2+ with Calixarenes

Author

Pradeep Kumar, Dipalee D. Malkhede, Ankita Rao, K. L. Ramakumar, and Nilesh V. Rathod

Subjects
Cadmium, General Chemical Engineering, Extraction (chemistry), Analytical chemistry, Supercritical fluid extraction, chemistry.chemical_element, General Chemistry, Industrial and Manufacturing Engineering, Supercritical fluid, Absorbance, chemistry.chemical_compound, chemistry, Nitric acid, Calixarene, Carbon dioxide, Nuclear chemistry
Abstract

In the present study, we explored the extraction of Cd2+ by supercritical fluid carbon dioxide using calixarenes as complexing agents in acidic medium. The optimum conditions for the extraction of cadmium were found to be 30 min of static extraction followed by 30 min of dynamic extraction, a temperature of 323 K, a pressure of 20.27 MPa, a CO2 flow rate of 2 mL min–1, and a nitric acid concentration of 0.1 M. Among the studied calixarenes, hexaacetylcalix[6]arene gave the maximum extraction efficiency of (90 ± 2)% in acidic medium. The presence of fluorinated pentadecafluoro-n-octanoic acid led to the enhancement of the extraction efficiency. The formation of a cadmium–calixarene complex was supported by energy-dispersive X-ray spectrocopy and UV–visible absorbance spectrocopy. Calixarene and its complex with cadmium were found to have distinctly different features in their scanning electron microscopy images. A solvent extraction study was carried out to study the thermodynamic aspects of complex format...

Published
2015

6. Complexation with calixarenes and efficient supercritical CO2extraction of Pb(<scp>ii</scp>) from acidic medium

Author

Ankita Rao, Karanam Lakshmi Ramakumar, Nilesh V. Rathod, Dipalee D. Malkhede, and Pradeep Kumar

Subjects
Supercritical carbon dioxide, Molar concentration, Chemistry, Metal ions in aqueous solution, Extraction (chemistry), Supercritical fluid extraction, Analytical chemistry, General Chemistry, Catalysis, Hexane, chemistry.chemical_compound, Calixarene, Materials Chemistry, Absorption (chemistry), Nuclear chemistry
Abstract

The present study describes the extraction of lead(II) from acidic medium with supercritical carbon dioxide using various calixarenes. It involves the investigation of the effect of temperature, acid molarity, and the metal to complexing agent molar ratio on supercritical fluid extraction efficiency. Efficient extraction of Pb(II) was observed for p-t-butylcalix(4)arene with (92 ± 3)% extraction at 323 K, 20.27 MPa, 30 minute static time followed by 30 minute dynamic time and a metal to complexing agent molar ratio of 1:5. The complexing ability of Pb(II) with calixarene was established by absorption and energy dispersive spectroscopy. The scanning electron micrograph of calixarene and the lead–calixarene complex was studied. The structure of the Pb(II)–calixarene complex has been proposed based on solvent extraction in hexane and IR spectroscopic analysis of the extract. Thermodynamic aspects of extraction were also studied and the extraction reaction was found to be entropy driven. Interference from other metal ions, on Pb(II) extraction behaviour, has been investigated. The developed method has been utilized for extraction of Pb(II) from real samples viz. paints, batteries, tobacco and wastewater.

Published
2014

7. Supercritical Carbon Dioxide Extraction of Uranium from Acidic Medium Employing Calixarenes

Author

Nilesh V. Rathod, Dipalee D. Malkhede, Vaibhavi V. Raut, Ankita Rao, and K. L. Ramakumar

Subjects
Molar concentration, Supercritical carbon dioxide, Process Chemistry and Technology, General Chemical Engineering, Extraction (chemistry), Inorganic chemistry, Supercritical fluid extraction, chemistry.chemical_element, Filtration and Separation, General Chemistry, Uranium, Hexane, chemistry.chemical_compound, chemistry, Nitric acid, Calixarene
Abstract

Various calixarenes were evaluated for the supercritical fluid extraction of uranium from nitric acid medium. The extraction efficiency was found to be affected by various parameters, namely pressure, temperature, CO2 flowrate, extraction time, and molarity of nitric acid. The addition of HPFOA (pentadecafluoro-n-octanoic acid) for the production of CO2-phillic fluorinated counter ion enhanced the extraction efficiency. Under optimized conditions (pressure of 200 atm, temperature of 323 K, 30 minutes of static time followed by 30 minutes of dynamic time, CO2 flowrate of 2 mL min−1, nitric acid molarity of 0.1 M) for uranium: calixarene: HPFOA mole ratio of 1:5:10, highest extraction efficiency could be obtained with p-tert.-butyl calix[6]arene (79.9%). Solvent extraction study with hexane as the organic phase indicated the formation of [UO2 (calixarene)]2+. In order to assess the suitability of the developed method to extract uranium in the presence of a host of other ions, extraction efficiency for other...

Published
2013

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