School Of Environment And Earth Sciences

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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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    Laccase immobilized magnetic iron nanoparticles: Fabrication and its performance evaluation in chlorpyrifos degradation
    (Elsevier Ltd, 2017) Das, A.; Singh, J.; Yogalakshmi, K.N.
    Chlorpyrifos degradation was studied using laccase immobilized on magnetic iron nanoparticles (CENPs). The magnetic iron nanoparticles (MNPs) prepared by co-precipitation method were characterized using Transmission electron microscopy (TEM), Scanning electron microscopy- Energy dispersive spectroscopy (SEM-EDS) and Thermogravimetric analysis (TGA). The size of the nanoparticles ranged between 10 and 15 nm. The MNPs were coated with chitosan, surface modified with carbodiimide (EDAC) immobilized with laccase enzymes. The chlorpyrifos degradation studies were performed in batch studies under constant shaking for a period of 12 h. Results of the study showed that laccase immobilized on magnetic iron nanoparticles were effective in degrading more than 99% chlorpyrifos in 12 h at pH 7 and 60 ?C. In the overall degradation percentage, MNPs contributed to 32.3% of chlorpyrifos removal while ENPs resulted in 58.8% chlorpyrifos degradation. Immobilization of enzyme decreased the overall activity of the free enzyme. The CENPs showed 95% activity after five repeated washing and hence possess good reusability potential. ? 2017 Elsevier Ltd