Dr Saroj Sekhar Behera | Institute of Minerals and Materials Technology (CSIR) (original) (raw)

Papers by Dr Saroj Sekhar Behera

Journal of Molecular Liquids, Nov 1, 2022

IOP conference series, Feb 1, 2018

Separation and Purification Technology, Feb 1, 2016

Leaching kinetics of neodymium was investigated from Nd-Fe-B scrap magnet using green solvent as ... more Leaching kinetics of neodymium was investigated from Nd-Fe-B scrap magnet using green solvent as CH 3 COOH. The Characterization study of the scarp magnet was performed by XRD and SEM-EDAX to ascertain the phase as Nd 2 Fe 14 B (31.05 % Nd, 65.15 % Fe and 0.66 % B). Influence of the factors such as CH 3 COOH concentrations (0.05 to 0.8 M), agitation speed (200 to 1000 rpm), particle size (45-150 µm), temperature (308 to 353K) and S/L ratio (1-5% (W/V)) affecting on leaching of Nd was investigated to obtain an optimum condition. Maximum yield (99.99%) of Nd along with definite extraction of Fe was resulted at the condition: Agitation speed: 800 rpm, S/L: 1% (W/V), temp. 353 K, 0.4 M CH 3 COOH and particle size: 106-150 µm). The key factors such as CH 3 COOH concentration and temperature appears to be critical on effective dissolution of both Nd and Fe from the scrap magnet phase. Leaching kinetic results showed best fit with the shrinking-sphere model () ensuring the overall leaching process is governed by surface chemical control mechanism. The activation energy determined from the experimental study was of +17.13 kJ/mol further more supports the proposed chemical control leaching process. Thermodynamics variables like ∆G 0 , ∆H 0 values determined from the Arrhenius plot at varied temperature indicating the feasibility of the leaching reaction of endothermic type. Linear dependence of the plot of log k ap on log 1/d o and a first order dependence of k ap with CH 3 COOH at 0.4M was derived from the above proposed leaching model.

DESALINATION AND WATER TREATMENT, 2017

Study on removal of anionic dye methyl orange (MO) from aqueous solution was investigated using i... more Study on removal of anionic dye methyl orange (MO) from aqueous solution was investigated using ion exchange resin Amberlite IRA-400 batch adsorption process. Effect of operating adsorption factors that influence on the adsorption process such as contact time (1-300 min), initial dye concentration (25-500 ppm), solution pH (2.5-11.5), resin dose (5-100 g/L) and temperature (293-353 K) were studied. The extent of MO adsorption was increased with increase in the contact time, agitation speed, temperature, initial dye concentration and adsorbent dose but decreased with increase/decrease of the solution pH (maximum at pH-6.5). Equilibrium data were analyzed by both Langmuir isotherm and Freundlich adsorption isotherm. The maximum monolayer adsorption capacity of Amberlite IRA-400 was resulted as 74.4 mg/g at 303 K. The value of separation factor (R L) from Langmuir equation and Freundlich constant (n) indicated on favorability of adsorption. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated and the positive value of ΔH° (4.13, 3.63 and 7.09 kJ mol-1) for corresponding initial MO dye concentrations: 50, 100 and 200 ppm, respectively, in the solution indicated that the adsorption was of endothermic in nature. Kinetics result revealed that the adsorption of MO is of pseudo second-order and chemisorptions type.

Separation and Purification Technology, 2020

Microwave assisted leaching investigation for the extraction of copper(II) and chromium(III) from... more Microwave assisted leaching investigation for the extraction of copper(II) and chromium(III) from spent catalyst, Separation and Purification Technology (2020), doi:

Applied Surface Science, 2019

A facile microwave-assisted combustion method was adopted to synthesize pure ZnO and Mgdoped ZnO ... more A facile microwave-assisted combustion method was adopted to synthesize pure ZnO and Mgdoped ZnO nanoparticles (NPs), and characterization of the NPs and the sorption behavior with Congo Red (CR) Azo dye was extensively investigated. The structure, morphology and chemical assay of the synthesized NPs were studied with respect to the pure and 2% Mg-doped ZnO samples. The X-ray diffraction pattern confirmed the presence of crystalline, cubic phase with fluorite structure of both the NPs. The morphological differences between the pure and Mgdoped ZnO NPs were evaluated by FE-SEM, which revealed that the NPs were in the nanoscale regime with irregular crystalline morphology having a grain size of ~18-45 nm. N 2 adsorption/desorption isotherms measured at-196°C suggested a Type II structure with limited hysteresis loops, likely due to some interparticle porosity. The BET SSA ZnO NPs obtained was found to be 32 m 2 g-1 , indicating about its potential in sorption processes. Batch adsorption study for the removal of CR carried out showed that, the Mg-doped NPs showed higher loading efficiency (125 mg.g-1) than the ZnO NPs (25 mg.g-1) counterpart. This was corroborated by the isotherm results in which the CR dye sorption followed a Freundlich Isotherm model for both undoped ZnO and Mg-doped ZnO NPs. The sorption of CR dye followed a pseudo-second order kinetics. The negative ΔG o (-31.91 and-109.41 KJmol-1) showed the feasibility of the adsorption process. The ΔH o was determined as +13.74 KJ/mol and 50.7 KJ/mol for ZnO NPs and Mg doped-ZnO NPs respectively, confirming the endothermic nature of the adsorption for removing CR dye from the solution.

AIP Conference Proceedings, 2017

Study on removal of Xylenol Orange (XO) from aqueous solution was investigated using synthesized ... more Study on removal of Xylenol Orange (XO) from aqueous solution was investigated using synthesized ZnO nano particle on batch adsorption process. The effectiveness of the microwave combustion route in producing cubic ZnO with fluorite structure was checked by the X-ray powder diffraction pattern and surface morphology of ZnO was investigated by Field Emission Scanning Electron Microscopy (FESEM) micrographs shows irregular nanoparticles with an average size of 18 nm. Effect of operating adsorption factors that influence on the adsorption process such as contact time (1-300 min), initial dye concentration (5-30ppm), solution pH (4.4-7.4), adsorbent dose (100-400mg/L) and temperature (293-333K) were studied. Equilibrium data were analysed by both Langmuir isotherm and Freundlich adsorption isotherm. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° was calculated and the negative value of ΔH° (−0.115 kJ mol−1) corresponds to an exothermic nature of the adsorption process and the positive values of ΔS° (0.053J...

Environmental Science and Pollution Research

Separation and Purification Technology, Dec 1, 2021

Abstract The extraction and leaching kinetics of V from the spent catalyst (3.06 %V, 10.01% Fe an... more Abstract The extraction and leaching kinetics of V from the spent catalyst (3.06 %V, 10.01% Fe and 0.52 % Mg) was investigated using organic citric acid. The characterization of the spent catalyst sample by XRD, EDAX and SEM was examined to ascertain the existence of V, Mg and Fe in the form of respective oxides. Different organic acids were tested to ensure the leaching performance towards extraction of V, Fe and Mg and based upon the efficacy, the metal extrication trend followed the order as; Citric acid > Tartaric acid > Acetic acid > Formic acid > Oxalic acid. The critical parameters such as citric acid concentration, agitation speed, temperature, S/L and particle size, affecting on either of the metal leaching was systematically examined at varying time extent to establish the leaching mechanism as well as for attaining suitable optimum condition for effective dissolution of vanadium. The leaching kinetics of V, Mg and Fe was governed by diffusion controlled mode while following to shrinking core model mechanism as evident from the correlation coefficient (R2 = 0.99) and the resultant activation energy (11.21 kJ/mole for V, 10.86 kJ/mole for Mg and 11.84 kJ/mole, for Fe). The dissolution behaviour of either of metals examined at various particle size ranges as well as citric acid concentrations follows the linearity trend with above proposed leaching kinetics model. More than 99% of Vanadium, 80% Fe and 75 % Mg leaching was resulted at the optimum condition: S/l: 4%, Citric acid: 1.0 M, temp: 373 K, Particle size: 46-75micron. The residue obtained after leaching at the above optimum condition was further analyzed by XRD and EDAX, indicating no peak due to Vanadium and confirms on almost all extraction of V from the spent catalyst phase.

Hydrometallurgy, May 1, 2019

Application of ultrasound and microwave assisted technology on the dissolution of neodymium (Nd) ... more Application of ultrasound and microwave assisted technology on the dissolution of neodymium (Nd) from waste magnet using organic reagent (s) was investigated. Amongst all the organic solvents, acetic acid appears to be effective while yielding higher Nd leaching efficiency. The characteristics pattern of XRD and SEM-EDAX study ascertained the magnet waste phase as Nd-Fe-B. Factors influencing the leaching of Nd such as time (0-5hr), [CH 3 COOH] (0.1-0.5M), ultrasound power (0W-120W), pulp density(S/L) (1-5%) and microwave power (450-900W) have been studied. Quantitative (~99.99%) Nd recovery was achieved under optimum ultrasound assisted leaching condition; time: 120 min, ultrasound power: 90W, [CH 3 COOH]: 0.4 mol/L and particle size range: 75-106 μm. Almost all Nd dissolution was attained at the suitable MW power of 900 Watt leading to reduce leaching time by 120 min than the regular mechanical stirring leaching (65.03% Nd resulted in 240 min). The enhancement of Nd leaching was mainly due to unique cavitation action of ultrasoundation and high heating energy produced from microwave to break the solid matrix of waste magnet, leading to diffuse the Nd metal ion into lixivaint phase as ascertained from SEM results of the magnet waste sample before and after ultrasound wave / microwave treatment.

Separation and Purification Technology, 2018

Comparative and synergistic solvent extraction of Sc(III) using two phosphoric acidic reagents su... more Comparative and synergistic solvent extraction of Sc(III) using two phosphoric acidic reagents such as di-(2-ethyhexyl) phosphoric acid and 2,4,4,tri-methyl,pentyl-phosphinic acid was investigated. Slope analysis method suggests a cation exchange reaction of Sc(III) with both extractants at a molar ratio of extractant: Sc(III) = 2.5:1 at equilibrium pH< 1.5. The plot of log D vs. log [Extractant] yield the slope (n) value as low as 1.2-1.3 and as high as n=7 at low and high extrcatant concentration level, respectively. Extraction isotherm study predicted the need of 2 stages at A: O=1:4 and A: O=1:3 using 0.1 M D 2 EHPA and 0.1 M Cyanex 272, respectively. Stripping of Sc (III) was carried out at varied NaOH concentration to ascertain the optimum stripping condition for effective enrichment of metal. The predicted stripping condition (2-stages with A: O=1:3 and 1:4 for D 2 EHPA and Cyanex 272, respectively) obtained from Mc-Cabe Thiele plot was further validated by 6-cycles CCS study. An actual leach solution of Mg-Sc alloy bearing 1.0 g/L of Sc (III), 2.5 g/L of Mg and 0.2 M HCl was subjected for selective separation of Sc at the optimum condition. The counter current simulation (CCS) study for both extraction and stripping of actual solution resulted quantitative separation of Sc with ~12 fold enrichment. The organic phase before and after loading of Sc (III) along with the diluents was characterized by FTIR to ascertain the phase transportation of Sc (III).

TiO 2 nanoparticles have been synthesized by co-precipitation method and is used as an adsorbent ... more TiO 2 nanoparticles have been synthesized by co-precipitation method and is used as an adsorbent for removal of toxic Congo Red (CR) dye. The resulting adsorbent TiO 2 was characterized by X-ray powder diffraction pattern, confirming the rutile phase of TiO 2 nanoparticle. Adsorption equilibrium data were evaluated by Langmuir isotherm and Freundlich adsorption isotherm. The kinetic data were analyzed using pseudo-first order, pseudo-second order and intraparticle diffusion equations. Kinetics result revealed that the adsorption of CR is of pseudo second-order and chemisorption type. Thermodynamic parameters such as ΔG o , ΔH o and ΔS o were calculated and the positive value of ΔH o (2.64 kJmol-1) corresponds to an endothermic nature of the adsorption process and the positive value of ΔS o (0.162 Jmol-1 K-1) reveals the increased randomness of the dye during adsorption process.

Removal of Bromocresol green (BCG) dye from aqueous solution has been investigated using activate... more Removal of Bromocresol green (BCG) dye from aqueous solution has been investigated using activated bio-sorbent Phragmites karka (PK). Batch adsorption method has been adopted and different parameters such as; pH of the solution, contact time, agitation speed, APK/BCG dose and temperature has been studied. From the resulted adsorption data the process is optimised and the transportation mechanism of BCG onto APK phase is proposed. In this study the bio-adsorbent PK is charred using H 2 SO 4 to produce activated Phragmites karka (APK) which appears as an effective adsorbent on enhancing the loading efficiency of BCG than PK without activation. The BCG adsorption efficiency is increased from 16.05 to 84.2 % with increasing in acidity of the solution and maximized at pH 0.5 of solution. Maximum loading capacity of 392.3 mg/g is resulted using APK as adsorbent while removing BCG at ambient condition. The PK, APK, BCG loaded APK, and BCG are characterized by SEM, UV-vis and FTIR to ascertain the adsorption process as well as mechanism. The absorption peak obtained at 3450 cm-1 due to ν (O-Hstr) of BCG was shifted to a broad band at 3270 cm-1 shows the conjugation of BCG on surface of the APK, confirming the transporation of BCG to APK Phase as resulted from FTIR analysis. From the adsorption kinetics study, the rate of BCG adsorption shows well fit to the pseudo second order model than pseudo first order kinetic model. The positive value of, ∆H o 2.49 kJ/ mole obtained by thermodynamic study reveals the endothermic nature of adsorption and and ∆S o 24.87 J.K-1 mol-1 shows the increase in degrees of freedom of BCG during adsorption. Equilibrium data are analysed by Langmuir, Freundlich and Tempkins adsorption isotherm to establish adsorption mechanism and the results shows best fit with Freundlich (R 2 =0.99) isotherm and reveals that the adsorption is of chemisorptions type.

A novel strategy for wastewater recycling by removing Chromium [Cr(III)] from water, utilizing th... more A novel strategy for wastewater recycling by removing Chromium [Cr(III)] from water, utilizing the treated water for agricultural purposes and the saturated adsorbent used as the catalyst for p-nitrophenol reduction was successfully incorporated for sustainable environmental application. Removal of Cr(III) by adsorption on Cymbopogon flexuosus waste material entrapped within sodium alginate beads was investigated. Sorption behavior of Cr(III) on to the biosorbent phase showed to follow pseudo first order kinetic model. The thermodynamic variables such as G (−2.59 kJ mol −1), H (4.57 kJ mol −1) & S (0.024 J mol −1 K −1) was evaluated and the corresponding values ensure on favoring endothermic nature of adsorption. Isotherm studies strongly supports on Freundlich model (R 2 = 0.99) rather than Langmuir isotherm model (R 2 = 0.93), Temkin (R 2 = 0.89) and Dubinin-Radushkevich (R 2 = 0.77) confirming on multilayer chemisorption behaviour with immobilized Cymbopogon flexuosus having the maximum loading capacity of 121.64 mg.g −1. The sorption of Cr(III) by immobilized Cymbopogon flexuosus was quantitative (99.9%) at the optimum condition: Cr(III) concentration:50 ppm, pH:4.5, agitation speed:150 rpm, temp.:298 K. The above sorption mechanism was well supported by the intraparticle diffusion model. Response Surface Methodology (RSM) was also introduced to investigate for optimization of process parameters during removal of Cr(III) from aqueous solution. The adsorbent material saturated with Cr(III) ascertained first order kinetics with k app value of 2.5 × 10 −1 min −1 for catalytic reduction of toxic p-nitrophenol to p-aminophenol. The phytotoxicity study of treated water on Zea mays plant has been analyzed and a considerable result obtained with regards to the usage of Cr(III) contaminated-water in plant growth. The change in the crystal structure, surface morphology and surface functional groups of the adsorbent before and after the process was analyzed and well ascertained by XRD, SEM and FTIR analysis. This investigation suggests the possible application of this low-cost material in fine chemical manufacturing.

Comparative study for solvent extraction of Sc(III) using two phosphoric acidic reagents such as ... more Comparative study for solvent extraction of Sc(III) using two phosphoric acidic reagents such as di-(2-ethyhexyl) phosphoric acid and 2,4,4,tri-methyl,pentyl-phosphinic acid was investigated. Slope analysis method suggests a cation exchange reaction of Sc(III) with both extractants at a molar ratio of extractant: Sc(III) = 2.5:1 at equilibrium pH < 1.5. The plot of log D vs. log [Extractant] yield the slope (n) value as low as n = 1.2-1.3 and as high as n = 7 at low and high extrcatant concentration level, respectively. Extraction isotherm study predicted the need of 2 stages at A: O = 1:4 and A: O = 1:3 using 0.1 M D2EHPA and 0.1 M Cyanex 272, respectively. Stripping of Sc(III) was carried out at varied NaOH concentration to ascertain the optimum stripping condition for effective enrichment of metal. The predicted stripping condition (2)-stages with A: O = 1:3 and 1:4 for D2EHPA and Cyanex 272, respectively) obtained from Mc-Cabe Thiele plot was further validated by 6-cycles CCS study. An actual leach solution of Mg-Sc alloy bearing 1.0 g/L of Sc(III), 2.5 g/L of Mg and 0.2 M HCl was subjected for selective separation of Sc at the optimum condition. The counter current simulation (CCS) study for both extraction and stripping of actual solution resulted quantitative separation of Sc with ∼12 fold enrichment. The organic phase before and after loading of Sc(III) along with the diluents was characterized by FTIR to ascertain the phase transportation of Sc(III).

The present research demonstrates the green synthesis of CeO 2 nanoparticles (NPs) using the Acac... more The present research demonstrates the green synthesis of CeO 2 nanoparticles (NPs) using the Acacia Concinna fruit extract by sol-gel route. The synthesized CeO 2 NPs are applied for the adsorptive removal of Reactive Blue (RB) azo dye and antimicrobial activities. The CeO 2 NPs are characterized using different techniques e.g. X-ray Diffraction Spectroscopy (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), UV-vis Spectroscopy, Scanning Electron Microscope (SEM), High Resolution Transmission Electron Microscopy (HR-TEM), Dynamic Light Scattering (DLS), Raman Spectroscopy, etc. The structural investigations (XRD) reveal the single-phase cubic fluorite-type structure of CeO 2 with 22.7 nm of crystallite size. The spectral analysis (FTIR) shows a strong vibration band below 849 cm − 1 owing to Ce-O-Ce stretching vibrations. A porous network-like morphology of the CeO 2 NPs is observed by SEM, where HR-TEM micrographs reveal that the nanoparticles are roughly spherical in nature. Raman spectroscopy confirms the vibrational mode of the cubic fluorite type structure of CeO 2 NPs at 462 cm − 1. The maximum loading capacity of CeO 2 NPS is 188.67 mg/g. The antibacterial activity of the CeO 2 NPs is evaluated against S. pneumoniae and E.coli, which shows 96.17 % and 96.89 % growth inhibition at 20 mg/ l.

Materials Science and Engineering: B

Separation Science and Technology, 2018

ABSTRACT The Mg–Sc alloy leach solution bearing 2.5 g/L Sc(III), 25.0 g/L Mg(II) and 0.5 M HCl wa... more ABSTRACT The Mg–Sc alloy leach solution bearing 2.5 g/L Sc(III), 25.0 g/L Mg(II) and 0.5 M HCl was subjected to investigate for separation of Sc(III) by hollow fibre liquid membrane (HFLM) followed by its recovery through oxalate precipitation route. Ionic liquid (IL) R4ND derived from commercial organo-phosphoric acid (D2EHPA) and aliquot-336 was used as carrier in this study. Equilibrium study ensures on extraction of Sc(III) as ScCl3 with association of 3 mole of R4ND in the extracted phase. The role of chloride and R4ND concentration appears to be critical while enhancing the Sc flux (JSc). The complex formation during extraction of Sc(III) into the carrier phase was confirmed from FTIR analysis. Maximum JSc of 10.41 × 10−5 mol/m2.s was obtained at the optimum condition: pH 4.0, 0.4 M R4ND, flow rate 150 mL/min., 6.0 M NaOH, Feed: Strip = 3:1 and after 90 min. of HFLM continuous run of almost all scandium separation from scrap solution was achieved on yielding threefold enrichment into the strip phase which bears ~7.49 g/L of scandium. The stripped solution resulted was precipitated using oxalic acid and substantially calcined to produce Sc2O3. The pure form of Sc2O3 produced in the present work was ensured from XRD analysis.

New and Future Developments in Microbial Biotechnology and Bioengineering: Microbial Biofilms