School Of Environment And Earth Sciences

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Author: search.filters.author.Babu, J. NagendraSubject: search.filters.subject.Adsorption

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    Adsorption of Zn(II) on Pristine and SPLP/TCLP Leached Rice Straw Biochar: an Interplay of Precipitation and Ion Exchange
    (Institute for Ionics, 2022-11-15T00:00:00) Bhardwaj, Akanksha; Nag, Shilpa; Hussain, Khadim; Arora, Meenu; Pandey, Puneeta; Babu, J. Nagendra
    The inorganic mineral content in biochar influences the adsorption of Zn(II) metal ions. Metal ion adsorption on mineral rich rice straw biochar is influenced upon washing. Rice straw slow pyrolysis biochar BC1-3, respectively, prepared at 400, 500, and 600��C, were leached under Toxicity Characteristic Leaching Procedure (TCLP) and Synthetic Precipitation Leaching Procedure (SPLP) conditions to furnish BT1-3 and BS1-3, respectively. The Zn(II) adsorption studies were carried out for pH and dose optimization, initial concentration, isotherm fit, and kinetic studies. The Zn(II) adsorption by B(C/S/T)1�3 showed Langmuir and Freundlich isotherm, with pseudo-second-order kinetics at optimum pH 5 and dose 1�g/L. The adsorption of Zn(II) followed the trend BC3(qm 47�mg/g) > BC2 > BC1 > BS2 > BS1 > BS3 > BT2 > BT1 > BT3 (qm 3.5�mg/g), i.e., metal ion adsorption decreased with extent of leaching. The Zn(II) adsorption on biochar involved precipitation as dominant factor for metal ion adsorption on the biochars followed by ion exchange and proton exchange. The precipitation of Zn(II) ions in case of BC1-3 is attributed to the pH of biochar, which increases with proportion of minerals to organic content in biochar. In case of biochar BS1-3 and BT1-3, ion exchange and proton exchange mechanisms driven by demineralization are responsible for Zn(II) adsorption. The adsorption mechanism for Zn(II) on biochar is supported by XPS, solid state NMR studies. Graphical Abstract: [Figure not available: see fulltext.] � 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
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    Removal of hexavalent chromium from aqueous solution using biomass derived fly ash from Waste-to- Energy power plant
    (Taylor & Francis, 2013) Vaid, Upma; Mittal, Sunil; Babu, J. Nagendra
    Fly ash from the agricultural waste-based Energy Power Plant has been studied for the adsorption of hexavalent chromium [Cr(VI)]. In order to maximize the Cr(VI) removal from simulated aqueous solutions, effects of various parameters i.e. adsorbent dose (10–40 g/L), contact time (5–90 min), variation in pH (1–5), and initial metal ion concentration (10–80 mg/L) on Cr(VI) adsorption were investigated by batch adsorption experiments. It was observed that adsorption of Cr(VI) on the selected adsorbent was dependent on pH. Before optimization of experimental conditions, the percent removal of Cr(VI) from the aqueous solution (10 mg Cr/L) was approximately 4%, which increased to approximately 99% after optimization of experimental conditions. Maximum adsorption was observed upon adding 10 g/L of adsorbent to a 60 mg Cr/L aqueous solution at pH 1.0 and contact time of 90 min at 200 rpm. Equilibrium adsorption data were well fitted in Langmuir isotherm model which substantiate monolayer adsorption of Cr(VI) on fly ash. Kinetics of Cr(VI) adsorption on fly ash follows pseudo-second-order reaction.
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    Removal of hexavalent chromium from aqueous solution: a comparative study of cone biomass of “Picea smithiana” and activated charcoal
    (Taylor & Francis, 2016) Mittal, Sunil; Vaid, Upma; Najar, Gh Nabi; Babu, J. Nagendra
    The present work investigates comparative adsorption efficiency of powdered cone biomass of Picea smithiana (PCBP) and activated charcoal (AC) for removal of hexavalent chromium (Cr) (Cr(VI)) from aqueous solution. The study indicates that PCBP has 76% removal efficiency for Cr as compared to AC. Particle size and SEM-EDX analyses were done to determine average particle size, surface morphology and elemental composition of PCBP. BET and FTIR analysis were carried out to elucidate the adsorption mechanism of Cr(VI) on PCBP. Ashing has been proposed as a method for managing waste of loaded PCBP generated in adsorption. Ashing studies showed the ash content of PCBP to contribute only 13% of the ash generated from loaded biomass. Further, a comparative study has been made indicating the adsorption efficiency of PCBP with previously reported bio-waste materials. The results of this study show that PCBP has high adsorption efficiency as compared to other bio-waste materials.