Department Of Environmental Science And Technology

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    Robust removal of cationic dyes by zinc ferrite composites in single and ternary dye systems
    (Elsevier B.V., 2023-05-02T00:00:00) Rimzim; Singh, Jandeep; Mittal, Sunil; Singh, Harminder
    For the continuous economic growth and development of society, clean and safe water is the basic necessity. Therefore, it is necessary to treat contaminated water. Magnetic ferrite composites with bio-waste materials are less explored in the area of research, so these need to be focused. In present study, novel magnetic Zinc Ferrite Pine Cone composite was prepared and used for the efficient removal of Crystal Violet, Malachite Green and Methylene Blue (Dye) from aqueous solution in single and ternary dye system. Various characterization techniques such as FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-Ray Diffraction), FE-SEM (Field Emission Scanning Electron Microscopy), EDS (Energy Dispersive Spectroscopy), TGA (Thermogravimetric Analysis) and BET (Brunauer-Emmett-Teller Analysis) are used for the structure elucidation of Zinc Ferrite and Zinc Ferrite Pine cone (Composite). Batch adsorption method was used for the removal of dyes in single and ternary dye system. Lagergren pseudo second order adsorption model fits best in the kinetic studies whereas, Langmuir adsorption isotherm showed better results with maximum adsorption capacity 76.33, 200 and 94.33 mg/g for single dye system and 9.46, 20.45 and 27.93 mg/g respectively in ternary dye system for dyes CV, MG and MB. Thermodynamic study confirmed about the spontaneous nature of adsorption process. The regeneration ability of the composite in both the systems was studied up to five cycles. So, it becomes clear that the composite (Zinc Ferrite Pine Cone) will work as best alternative for dyes removal in single and ternary dye system. � 2023 Elsevier B.V.
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    Removal of Methylene Blue from aqueous solution by Fe3O4@Ag/SiO2 nanospheres: Synthesis, characterization and adsorption performance
    (Elsevier B.V., 2018) Saini, J.; Garg, V.K.; Gupta, R.K.
    In this study, silver silica coated magnetite (Fe3O4@Ag/SiO2) nanospheres were synthesized employing sonication method and their performance was evaluated as nanoadsorbents for the removal of Methylene Blue in batch mode experiments. The physical characteristics of these nanospheres were studied using XRD, SEM, EDX, TEM, and FTIR techniques. The Fe3O4@Ag/SiO2 nanospheres were capable to remove 99.6% Methylene Blue from aqueous solution at pH 7. A possible mechanism for the adsorption of Methylene Blue onto Fe3O4@Ag/SiO2 has been proposed. The adsorption equilibrium and kinetics were studied for experimental data. The removal process followed Langmuir isotherm with maximum monolayer adsorption capacity of 128.5 mg/g. Experimental kinetic data fitted well to Pseudo-second-order and Intraparticle diffusion models. The values of thermodynamic parameters, viz., ?G0, ?S0 and ?H0 confirmed spontaneous, endothermic and feasible adsorption of Methylene Blue under studied experimental conditions. The Fe3O4@Ag/SiO2 nanospheres were regeneratable and reusable for five successive cycles. ? 2017 Elsevier B.V.
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    Removal of Congo red and Brilliant green dyes from aqueous solution using flower shaped ZnO nanoparticles
    (Elsevier Ltd, 2017) Kataria, N.; Garg, V.K.
    This work reports preparation and characterization of ZnO nanoparticles prepared by low temperature hydrothermal methods and their application for anionic dye (Congo red) and cationic dye (Brilliant green) removal from aqueous medium. The adsorption capacity of ZnO nanoparticles for Congo red dye and Brilliant green dye was up to 71.4 and 238 mg/g, respectively under selected process conditions. Dye adsorption behaviour has been explained applying different isotherms. Freundlich isotherm model best fitted to the dye removal data. Adsorption kinetics of both dyes is well explained by pseudo-second order model. Physical adsorption has been investigated using thermodynamic parameters viz., Gibb's free energy (?G?), enthalpy (?H?) and entropy (?S?). The reusability of ZnO nanoparticles was examined upto three cycles. ? 2017 Elsevier Ltd. All rights reserved.
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    Removal of Orange G and Rhodamine B dyes from aqueous system using hydrothermally synthesized zinc oxide loaded activated carbon (ZnO-AC)
    (Elsevier Ltd, 2017) Saini, J.; Garg, V.K.; Gupta, R.K.; Kataria, N.
    This study reports the synthesis of zinc oxide loaded activated carbon (ZnO-AC) using hydrothermal method and its use to remove organic dyes [Orange G (OG) and Rhodamine B (Rh-B)] from the aqueous system under varying process conditions. ZnO-AC nanoparticles were characterized using XRD, SEM, EDX, DLS, and FTIR. The Langmuir adsorption model was best fitted to the experimental data for both the dyes. Langmuir adsorption capacity (qmax) for OG and Rh-B was 153.8 and 128.2 mg/g, respectively. The rate of adsorption was investigated by various models namely pseudo-first-order, pseudo-second-order and intraparticle diffusion model. Rate mechanism was described by pseudo-second-order model for both the dyes. Thermodynamic studies suggested that removal of Rh-B onto ZnO-AC was endothermic up to a temperature of 40 ?C while OG removal decreased with increase in temperature. Negative values of ? G0 for adsorption of dyes suggested spontaneous adsorption processes. ? 2017 Elsevier Ltd. All rights reserved.
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    Preparation, characterization and potential use of flower shaped Zinc oxide nanoparticles (ZON) for the adsorption of Victoria Blue B dye from aqueous solution
    (Elsevier B.V., 2016) Kataria, N.; Garg, V.K.; Jain, M.; Kadirvelu, K.
    In present work, the performance and effectiveness of flower-shaped Zinc oxide nanoparticles (ZON) synthesised by hydrothermal method was evaluated for the adsorption of Victoria Blue B (VB B) dye from aqueous solution. ZON were characterised by using XRD, FTIR, SEM, EDX and DLS. Batch mode adsorption experiments were carried out to optimise the process conditions viz., pH, adsorbent dose, dye concentration, temperature, etc. The adsorption of cationic dye onto ZON surface was illustrated by Langmuir and Temkin isotherm models. The mechanism of dye adsorption onto the nanoparticles was explained by pseudo-second order kinetic model (R2???0.997). The thermodynamic parameters including Gibb's free energy (?G0), enthalpy (?H0), and entropy (?S0) were studied at different temperatures (10?70??C). The maximum adsorption capacity of VB B dye onto ZON was achieved up to 163?mg/g at pH 6.0 and temperature 27???1??C. ? 2016 The Society of Powder Technology Japan