Publications by authors named "P K Parhi"

29 Publications

Environmental friendly approach for selective extraction and recovery of molybdenum (Mo) from a sulphate mediated spent Ni-Mo/AlO catalyst baked leach liquor.

Authors:
P K Parhi P K Misra

J Environ Manage 2022 Jan 11;306:114474. Epub 2022 Jan 11.

Centre of Studies in Surface Science and Technology, School of Chemistry, Sambalpur University, Jyoti Vihar, 768 019, Odisha, India. Electronic address:

Solvent extraction separation of molybdenum (Mo) from the sulphate mediated leach solution bearing Aluminium (Al) and Nickel (Ni) was carried out using N-Methyl-N, N, N-tri-octyl-ammonium chloride. Extensive investigation for extraction study molybdenum in the function of time, Eq.pH, extractant concentration, diluents, temperature, strip solution concentration and phase ratio(A:O) for both extraction and stripping was examined to attain a suitable condition on its selective and enriched extraction. As per the equilibrium study and increasing trend of Eq. pH (pH) at the correspondence initial pH, it was apparent about association of 1 mol of H ion during extraction which with was further supported on extraction of Mo as HMO at the pH of 3.48. The association of 1 mol of exrractant during the extraction of Mo was also well evident from the slope analysis study. This indicates about anion exchange phenomenon due to Cl ion of the N-Methyl-N, N, N-tri-octyl-ammonium chloride (extractant) with HMo from aqueous phase during complex formation reaction. The FTIR of the organic sample before and after extraction further confirms in support of the complex formation of the molybdenum with the extractant during extraction. The extraction isotherm was constructed at optmum extraction condition: pH of 3.48 with 0.08M N-Methyl-N, N, N-tri-octyl-ammonium chloride predicts on need of 2-counter current stages for quantitative extraction of Mo at A:O = 3:1. To investigate the regeneration behaviour of adopted extractant along with enriched stripping of molybdenum, ammoniacal reagents were used in stripping study. The stripping of Mo showed promising and efficient using the mixture of the ammoniacal reagents (NHOH + NHCl) over the either of the solo reagents. The stripping Mc-Cabe Thiele diagram was plotted using 2M NHOH + NHCl ensures on quantitative stripping of Mo at SO: SS = 2:1 at 2 no. of stages. Both extraction and stripping isotherm results are validated at predicted isotherm conditions by 6-cycles counter current simulation (CCS) study leading to obtain 6-fold enrichment of Mo in stripped solution phase. The subsequent enriched content of Mo (∼60 g/L) in stripped solution phase was precipitated out followed by calcinations 400 °C to obtain a high pure MoO. The recovered calcined product as MoO resulted through the proposed processing approach was as ascertained from XRD analysis.
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http://dx.doi.org/10.1016/j.jenvman.2022.114474DOI Listing
January 2022

Valorization of renewable resources to functional oligosaccharides: Recent trends and future prospective.

Bioresour Technol 2021 Dec 22;346:126590. Epub 2021 Dec 22.

Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram 695 019, Kerala, India. Electronic address:

Lignocellulosic wastes have the ability to be transformed into oligosaccharides and other value-added products. The synthesis of oligosaccharides from renewable sources bestow to growing bioeconomies. Oligosaccharides are synthesized chemically or biologically from agricultural residues. These oligosaccharides are functional food supplements that have a positive impact on humans and livestock. Non-digestible oligosaccharides, refered as prebiotics are beneficial for the colonic microbiota inhabiting the f the digestive system. These microbiota plays a crucial role in stimulating the host immune system and other physiological responses. The commonly known prebiotics, galactooligosaccharides (GOS), xylooligosaccharides (XOS), fructooligosaccharides (FOS), mannanooligosaccharides (MOS), and isomaltooligosaccharides (IOS) are synthesized either through enzymatic or whole cell-mediated approaches using natural or agricultural waste substrates. This review focusses on recent advancements in biological processes, for the synthesis of oligosaccharides using renewable resources (lignocellulosic substrates) for sustainable circular bioeconomy. The work also addresses the limitations associated with the processes and commercialization of the products.
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http://dx.doi.org/10.1016/j.biortech.2021.126590DOI Listing
December 2021

Effect of calcination temperature on morphology and phase transformation of MnO nanoparticles: A step towards green synthesis for reactive dye adsorption.

Chemosphere 2022 Feb 8;288(Pt 2):132472. Epub 2021 Oct 8.

Department of Chemistry, School of Applied Sciences, KIIT Deemed to Be University, Bhubaneswar, 24, Odisha, India. Electronic address:

Green synthesis of manganese oxide nanoparticles (NPs) was carried out by sol-gel method using Acacia Concinna fruit extract for removal of reactive dye. The effect of calcination temperature on its morphology was investigated. α-MnO and MnO NPs were synthesized at 400 °C and 900 °C respectively and were characterized by PXRD, SEM, TEM, FTIR, BET, Raman and TGA. As-synthesized MnO NPs were investigated for the adsorption of Reactive Blue 21 (RB-21) dye. The effect of pH, adsorbent dose, agitation speed, initial dye concentration and temperature on dye removal was explored. pH was calculated from zeta potential study showing positive surface charge below pH 3.18 resulting in electrostatic force of attraction between adsorbate and adsorbent. Both linear and non-linear regression approaches were utilised for the fitting of kinetic models and adsorption isotherms. Adsorption data follows a pseudo second order kinetics and fits well with the Freundlich isotherm model. Thermodynamic parameters such as ΔH, ΔS and ΔG were determined. The dye removal efficiency, in case of MnO NPs at pH 3.0 was obtained to be 98% whereas for MnO, no such dye adsorption was observed. The mechanism of adsorption was studied theoretically confirming π-π interaction and H-bonding between the MnO and RB dye molecules.
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http://dx.doi.org/10.1016/j.chemosphere.2021.132472DOI Listing
February 2022

Sustainable Transportation, Leaching, Stabilization, and Disposal of Fly Ash Using a Mixture of Natural Surfactant and Sodium Silicate.

ACS Omega 2021 Sep 24;6(35):22820-22830. Epub 2021 Aug 24.

Department of Chemistry, Sukanti Degree College, Subarnapur 767017, Odisha, India.

The present study evaluates the transportation, leaching, and stabilization ability of novel saponin extracted from the fruits of . To enhance the dispersing behavior of the fly ash slurry (FAS) at a lower dosage of sodium silicate, was incorporated in FAS. In addition to the rheological study, an attempt has been made to remove heavy metals through leaching for the safe disposal of FAS. Critical factors such as the fly ash (FA) concentration, saponin dosage, surface tension, ζ potential, temperature, and combination of saponin and sodium silicate, affecting the rheology of FAS, were extensively studied. The addition of a nonionic natural surfactant saponin has been proved to enhance the wettability of FA particles by decreasing the surface tension of FAS. The obtained rheology results were compared with the stabilization yield of the previously reported commercial surfactant cetyltrimethylammonium bromide. The incorporation of sodium silicate in the FAS system was found to be phenomenal in the settling and stabilization of FAS, thereby developing reaction products like sodium aluminum silicate (N-A-S). This facilitates the sustainable disposal of FA preventing air pollution after dewatering. The formation of N-A-S was further supported by scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies.
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http://dx.doi.org/10.1021/acsomega.1c03241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8427790PMC
September 2021

Environmentally friendly comprehensive hydrometallurgical method development for neodymium recovery from mixed rare earth aqueous solutions using organo-phosphorus derivatives.

Sci Rep 2020 10 9;10(1):16911. Epub 2020 Oct 9.

Convergence Research Center for Development of Mineral Resources (DMR), Korea Institute of Geoscience & Mineral Resources (KIGAM), Daejeon, 34132, Korea.

Rare earth elements (REEs) have obtained a greatest significant in human lives owing to their important roles in various high technology applications. The present method development was deal technology important REEs such as neodymium, terbium and dysprosium, selective extraction with possible separation and recovery studies, successfully. The chloride mediated mixed aqueous solution containing 1500 mg/L each of REEs such as Nd, Tb and Dy was subjected at selective separation of Nd from other associated REEs. Three organo-phosphorous based commercial extracting agents such as Cyanex 272, PC 88A and D2EHPA, were employed for the extraction, possible separation and recovery of rare earth elements. A comparative extraction behavior of all these three extractants as function of time, pH influence, extractant concentration, temperature and diluents were systematically investigated. The extraction tendency of organo-phosphorus reagents towards the extraction of either of the REEs follows of the sequence as: D2EHPA > PC 88A > Cyanex 272. The thermodynamic behavior of either of the extractants on liquid-liquid extraction processing of REEs was investigated and thermodynamic calculations were calculated and presented. Substantial recovery of neodymium oxalate followed by its calcined product as neodymium oxide was ascertained from XRD study and SEM-EDS analysis.
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http://dx.doi.org/10.1038/s41598-020-74041-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7547677PMC
October 2020
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